Each marker on the ring is one counted review, coloured by its verdict.

Casio

G-Shock GA-2100

GA-2100-1A145.4mmquartz$99 list priceAnnounced November 2019

An all-black resin G-Shock with an octagonal bezel, analog hands over a small digital display, and a 200m, shock-resistant Carbon Core Guard case that is slim for a G-Shock. The Royal Oak-like shape earned it the 'CasiOak' nickname, and it became a cult affordable watch.

Casio product page

Creator Consensus

Very positive

10 reviews: 10 positive, 0 mixed, 0 negative. 10 of 10 recommend it.

Every reviewer recommends the GA-2100. Most call it exceptional value and among the most comfortable G-Shocks, and several say it wears more compactly than its dimensions suggest, helped by a slim case and supple strap. Most have mixed feelings about the dial: several fault the small digital display, weak hand lume and the reduced legibility of blacked-out or coloured variants.

Where they differ. Several reviewers find the thin resin strap comfortable, while a couple say it is not especially soft. Likewise, several praise the rich feature set, but a couple find the functions fiddly enough to need the manual.

Most praised

Exceptional value at an accessible price8 of 10
- Time+Tide Highlights its affordability as part of its appeal.it won’t break the bankRead it in context
- Watchfinder & Co. Considers the price the biggest driver of its appeal, accessible to nearly anyone.At $100, it ranges from just about affordable to a whimRead it in context
- Teddy Baldassarre Calls it good value at around a hundred dollars.this is just good value at a hundred dollarsWatch from 12:04
- Quill & Pad Believes it is the best watch available under $100.Is it the best watch under $100? I believe so.Read it in context
- Quill & Pad Affordable price, especially with frequent discounts, makes it great value and fun.It is fun and offers great value for moneyRead it in context
- Just One More Watch Considers it one of the best G-Shocks available at its $99 price.one of the best G shops on the market for that priceWatch from 8:19
- Watch Geek Considers the $99 price affordable and low-risk.this variant is quite affordable at $99Watch from 7:24
- Page 29 Watches Impressed by how much the watch offers for its price.You get a lot for your money with this watch.Watch from 0:00
- Worn & Wound Considers it an affordable small luxury.at a price point where this small luxury won’t be painfulRead it in context
Among the most comfortable G-Shocks to wear7 of 10
- Time+Tide Ranks it among the most comfortable G-Shocks released in recent memory.it is far and away one of the most comfortable watchesRead it in context
- Worn & Wound Finds it remarkably comfortable compared with bulky G-Shocks.it’s incredibly comfortable to wearRead it in context
- Fratello Prefers wearing it to their many square G-Shocks and far prefers it to Mudmasters.it blows the socks off the hulking Mudmasters that call my watch box homeRead it in context
- Fratello Credits its size and round case for how comfortably it sits, finding it more wearable than other recent Casios.I do find it all the more wearable than the many noveltiesRead it in context
- Just One More Watch Says it wears better than any G-Shock worn so far.this one wears better than any G that I've worn so farWatch from 3:31
- Just One More Watch Conforms to the wrist better than the standard 5600.it curves it conforms to the rest much better than the standard G shop 5600Watch from 7:50
- Quill & Pad Delivers the full G-Shock experience in a comfortable package.a package that feels great on the wristRead it in context
- Watch Geek Finds it wears very comfortably, helped by low weight and thinness.I have to admit it wears very comfortablyWatch from 4:03
- JustBlueFish Watch Reviews Finds it lightweight, comfortable and relatively thin on the wrist.it's lightweight it's comfortable It's relatively thinWatch from 6:15
- Worn & Wound Lighter and easier to wear yet still feels robust.The GA-2100 may be lighter and easier to wear, but it’s anything but delicate.Read it in context
Wears more compactly than its dimensions suggest5 of 10
- Time+Tide Says it wears much smaller than 45mm and fits nearly any wrist size.ensuring a comfy fit on pretty much any sized wristRead it in context
- Teddy Baldassarre Finds the fit compact despite large on-paper numbers, helped by light weight.the fit is actually rather compact and wearability is further enhancedWatch from 1:27
- Quill & Pad Short lug-to-lug makes it feel more compact on the wrist than the numbers suggest.the lug-to-lug measurements make it feel more compact on the wristRead it in context
- Just One More Watch Finds it light despite the large 45mm diameter.it is nice and light in spite of that initially foreboding diameterWatch from 3:31
- Worn & Wound Narrow top and bottom make it feel small at sensitive parts of the wrist, like an oval watch.The watch feels small at the most sensitive parts of the wristRead it in context
- Time+Tide Short lugs let the case taper nicely around the wrist.The short lugs allow it to taper nicely with the curve of your wristRead it in context
Thin, supple resin strap is comfortable5 of 10
- Time+Tide Finds the corrugated resin strap very comfortable.is very comfortable on the wristRead it in context
- Fratello Suggests the supple strap contributes to the pleasant wearing experience.Maybe it came down to the supple strap.Read it in context
- Teddy Baldassarre Praises the thin, pliable resin strap as very comfortable.thin and really pliable providing a very comfortable fit around the wristWatch from 2:53
- Worn & Wound Thinner strap than standard G-Shocks makes it more wearable.it’s quite a bit thinner than the standard plastic strap G-Shock usesRead it in context
- Just One More Watch Finds the resin band considerably softer than the one on the 5600.the band itself I think is considerably softer than the one on the basic GWatch from 8:19
Slim case by G-Shock standards4 of 10
- Time+Tide Finds the slim profile a standout feature.the profile is remarkably slim, making it a stone-cold killer in my bookRead it in context
- Time+Tide Sees the case as very thin by G-Shock standards.the case is wafer-thin compared to most other watchesRead it in context
- Worn & Wound Considers it one of the slimmest G-Shocks, a key reason for its appeal.this is one of the most svelte G-Shocks Casio has ever madeRead it in context
- Quill & Pad Considers the thin case and light weight impressive.This is all impressive.Read it in context
- JustBlueFish Watch Reviews Considers the 11.8mm thickness quite reasonable.thickness of about 11.8 millimeters which I have to say is not bad at allWatch from 2:25
- Quill & Pad Finds the size excellent and thinner than many watches while keeping a rugged look.thinner than a lot of watches out thereRead it in context
Octagonal case and bezel look handsome4 of 10
- Watchfinder & Co. Considers the octagonal shape the second major reason for the watch's popularity.the shape that gave it the nickname “CasiOak.”Read it in context
- Fratello Considers the case shape really handsome.The case shape is really handsome.Read it in context
- Quill & Pad Thinks the octagonal bezel looks great.I must say it looks greatRead it in context
- Teddy Baldassarre Highlights the porthole-style bezel as the watch's appealing feature.the appealing aspect of this particular g-shock is the porthole style bezelWatch from 2:24

Show 23 more

Suits smaller wrists unlike most G-Shocks3 of 10
- Time+Tide Notes it no longer requires a large wrist to pull off, unlike many G-Shocks.No longer do you need a wrist like Dwayne Johnson to pull the look off.Read it in context
- Just One More Watch Notes it does not feel big or chunky on a 7-inch wrist.this one doesn't feel big and chunky at all thanks to that 12 millimeter thicknessWatch from 7:22
- Page 29 Watches Surprised how well it fits a skinny 17cm wrist.pleasantly surprised when I put it on that the watch fits so well to my wristWatch from 2:52
Retains full G-Shock toughness and water resistance3 of 10
- JustBlueFish Watch Reviews Praises the typical G-Shock toughness and shock resistance.it offers the same outstanding shock resistance that you'd expect from a G-ShockWatch from 1:00
- Watch Geek Values that it keeps full G-Shock shock resistance and water resistance.this watch is a fully fledged DG shock with all the shock resistanceWatch from 4:59
- Page 29 Watches Considers the 200m water resistance suitable for divers and water sports.this watch is definitely suitable for divers and for those who enjoy water sportsWatch from 4:49
Surprisingly rich feature set3 of 10
- Just One More Watch Praises the large amount of functionality compared with basic G-Shocks.heaps and heaps of functionality that you don't get with the basic G'sWatch from 8:19
- Quill & Pad Was surprised by how much the watch can do.the breadth of what the watch could do was eye-openingRead it in context
- Teddy Baldassarre Values the range of features and toughness.it has a myriad of features it's classic g-shock design it could take a beatingWatch from 12:04
Effective backlight for the digital display3 of 10
- Worn & Wound Likes the backlight.an effective and quite enjoyable backlightRead it in context
- Page 29 Watches Finds the double LED illumination very useful in the dark.very useful in the darkWatch from 6:16
- Watch Geek Finds the LED backlight good for the digital display but useless for the analog hands.the LED backlight does a great job at making the digital display visibleWatch from 6:25
Analog layout stays clear and legible3 of 10
- Time+Tide Asymmetric layout stays legible despite displaying a lot of information.asymmetric layout that is highly legible, despite the amount of informationRead it in context
- Time+Tide White hands and grey markers contrast well against the black dial.white hands and grey hour markers contrast nicely against the black dialRead it in context
- Page 29 Watches Calls the dial layout the favourite part, with clearly legible hands and markers.The structure and layout of the dial is personally my favorite part of the watch.Watch from 2:52
- Fratello Finds the display interesting and intuitively arranged.how interesting and intuitively arranged the display isRead it in context
Raised indices give the dial real depth3 of 10
- Worn & Wound Raised indices add depth and legibility.they’re raised, giving the dial a bit of depth and lending an extra touch of legibilityRead it in context
- Quill & Pad Applied indices give the dial good depth and visual interest.They are applied and provide a good amount of depthRead it in context
- Page 29 Watches Appreciates the stepped indices and layered layout for a real sense of depth.The way these features are laid out creates a real sense of depthWatch from 3:22
Integrated strap suits the design3 of 10
- Teddy Baldassarre Thinks the resin strap suits the design cohesively and sees little reason to swap it.the resin pairing just works well with the totality and cohesiveness of the designWatch from 3:22
- Quill & Pad Integrated strap design adds to the watch's appeal.G-Shock has used an integrated design for the strap and this adds to its attractivenessRead it in context
- Page 29 Watches Finds the resin straps brilliantly integrated with solid, practical design details.The straps themselves are brilliantly integrated to the rest of the watchWatch from 4:19
Strikingly cool and good-looking3 of 10
- Teddy Baldassarre Considers it incredibly fashionable and good looking.also is incredibly fashionable it just looks greatWatch from 11:36
- Just One More Watch Considers the watch crushingly cool despite the legibility issues.I don't care this watch is crushingly coolWatch from 1:08
- Watch Geek Ranks it among the best-looking G-Shocks since the original square.this has to be one of the best-looking g shock s-- casio has releasedWatch from 1:14
- Just One More Watch Says it looks great and wears fantastically.it wears fantastically it looks greatWatch from 9:17
Octagonal design rooted in Casio's own history3 of 10
- Watchfinder & Co. Argues the design traces back to the F-91, with its integrated strap and eight sides.the CasiOak isn’t wholly unoriginalRead it in context
- Quill & Pad Appreciates that the octagonal shape comes from G-Shock's own 1980s history.I love that the shape was previously used by G-Shock in the 1980sRead it in context
- Watch Geek Appreciates the return to the square's functional design formula.This watch goes back to the simple formula of making a regular watchWatch from 2:10
- Watchfinder & Co. Sees the watch's nostalgic Casio identity as something a copycat brand could never replicate.they’d still be missing a core tenet of the CasiOak’s identity: nostalgiaRead it in context
Channels Royal Oak spirit without copying it3 of 10
- Time+Tide Sees it as playful 'high fashion, low rent' access to a luxury aesthetic without being a straight homage.you get access to an otherwise off-limits category but in an obviously tongue-in-cheek wayRead it in context
- Worn & Wound Finds it bold and brash, with some of the early Royal Oak spirit.it’s bold and brash carries with it at least some of the spirit of the early Royal OaksRead it in context
- Quill & Pad Softer octagon distinguishes it from the Royal Oak.so it doesn’t just look like a homageRead it in context
Welcome return to sensible case dimensions2 of 10
- Watch Geek Loves the case dimensions.I personally love the dimensions of this thingWatch from 3:35
- Watch Geek Glad Casio is following the trend back to normal watch sizes.I'm glad casio is doing the sameWatch from 3:07
- Worn & Wound Notes it is large but notably smaller than many ~50mm G-Shocks with awkward geometry.significantly smaller than many popular G-Shocks, which measure closer to 50mmRead it in context
Recessed crystal well protected against knocks2 of 10
- Teddy Baldassarre Appreciates the crystal sitting below the bezel to guard against chips and scratches.which protects the crystal from getting shipped or scratched a convenient featureWatch from 4:46
- Page 29 Watches Notes the raised bezel helps protect the crystal.The raised bezel does also provide a decent little cover for the crystalWatch from 1:53
- Page 29 Watches Reports the crystal survived hikes and door-frame knocks without marks.the crystal is holding up nicely with no visible damage or scratches so farWatch from 2:23
Carbon Core Guard construction adds appeal2 of 10
- Worn & Wound Sees the Carbon Core Guard construction as critical to the case's appeal and promising for the future.the possibilities are nearly endlessRead it in context
- Just One More Watch Enjoys having some carbon on the wrist at this price.it's cool to have a little bit of carbon on your wristWatch from 4:28
Thin enough to slip under a shirt cuff2 of 10
- Worn & Wound Thin enough to slip under a shirt cuff.the case has an undeniable ability to slide gracefully under a shirt cuffRead it in context
- Quill & Pad Slips under a cuff at the office yet suits beach or hiking.fits under a cuff if I end up wearing it to the officeRead it in context
Versatile, tough everyday wearer2 of 10
- Teddy Baldassarre Calls it one of the most versatile all-rounders for the price.one of the most versatile all-arounders you can have for the priceWatch from 1:54
- Quill & Pad Worn far more than expected, even more than a Rolex Milgauss.considerably more than the Rolex Milgauss I also have in the collectionRead it in context
- Quill & Pad Sees it as a tough, good-looking daily wearer.a daily wearer that can withstand anything you throw at itRead it in context
Hand-shift clears view of digital display2 of 10
- Just One More Watch Likes the hand-shift feature that moves the hands clear of the digital display.one cool feature is that if you're using that digital displayWatch from 5:55
- Page 29 Watches Likes the hand-shift feature for viewing the digital display.There's also a cool hand shift featureWatch from 6:44
Lumed hands glow usefully in the dark2 of 10
- JustBlueFish Watch Reviews Notes the hands are lumed and glow in the dark.the handset does have Loom and it does glow in the darkWatch from 4:49
- Just One More Watch Finds the hand lume stronger than on other ana-digi Casios owned.it's certainly more powerful than some of the other Annie digi castlesWatch from 5:25
Simpler and less toy-like than typical G-Shocks2 of 10
- Watch Geek Welcomes the simpler, less toy-like approach versus chunky modern G-Shocks.a whole new market of people wanting something simpler and less toyWatch from 2:10
- Watch Geek Finds it looks more serious than other G-Shocks while keeping G-Shock identity.looks a lot more serious than other G shocks while still looking like a G shockWatch from 2:39
- Quill & Pad Simplified layout is less busy than other analog G-Shocks and more attractive.does a great job at becoming more versatile and aesthetically pleasingRead it in context
True to G-Shock's rugged identity2 of 10
- JustBlueFish Watch Reviews Finds it very cool and modern, and a true embodiment of the G-Shock identity.it's extremely cool it's very modern and it exemplifies what it means to be a Casio G-ShockWatch from 7:14
- Page 29 Watches Considers the rugged design visually impressive and true to G-Shock's toughness image.This watch is visually very impressive with a rugged designWatch from 1:26
Case, dial and strap form a cohesive whole2 of 10
- Worn & Wound Appreciates how dial, case and strap blend into a single cohesive object.the dial and case (and the strap) seem to all be part of the same objectRead it in context
- Page 29 Watches Likes the matching colour across strap, case, bezel and dial as uniform and smart.the strap, case, bezel, and dial all being the same color is a really nice design choiceWatch from 3:50
Reliable, accurate quartz module2 of 10
- Teddy Baldassarre Considers the module among the most reliable at this price, though basic.you're clearly getting one of the most reliable movements produced by a powerhouseWatch from 11:06
- Page 29 Watches Considers the claimed ±15 seconds per month accuracy acceptable.which doesn't sound too bad to meWatch from 4:49
Quick-release spring bars a welcome first1 of 10
- Just One More Watch Welcomes quick-release spring bars as a G-Shock first.quick-release spring bars again a first for a Casio g-shockWatch from 4:56
Luxury-level cool for a fraction of the cost1 of 10
- Watchfinder & Co. Sees it as the sweet spot compared with pricier G-Shocks and luxury watches.But this here, this GA-2100, is the sweet spot.Read it in context
- Watchfinder & Co. Loves that it offers comparable cool to luxury pieces for a fraction of the price.being able to buy something just as cool for a fraction of the priceRead it in context

Most criticised

Small digital display is hard to read3 of 10
- Worn & Wound The LCD is nearly unreadable without backlight unless in direct sunlight.the screen is virtually impossible to read without the backlightRead it in context
- JustBlueFish Watch Reviews Finds the negative digital display small and hard to read except in bright light.it's hard to read in all but the most well-lit environmentsWatch from 4:20
- Page 29 Watches Finds the digital display hard to read in dim light or cloudy conditions.the digital display can be a bit tricky to seeWatch from 6:16
- Worn & Wound Screen is too small to clearly show timer or timezone information.the screen is just too small to coherently display all of the informationRead it in context
Hand lume is weak and fades quickly3 of 10
- Worn & Wound Feels the lume on the hands could be stronger.thanks to some lume that could be strongerRead it in context
- Quill & Pad Lume on the hands is disappointing.The hands are filled with lume, but it is not greatRead it in context
- Page 29 Watches Finds the lume fades quickly, making it largely redundant at night.So, it's a little bit redundant at night by the time you actually need it.Watch from 5:47
Blacked-out and coloured variants sacrifice legibility3 of 10
- Just One More Watch Finds the blacked-out version not very legible.it isn't the most legible of the models that are availableWatch from 7:22
- Watch Geek Judges the stealth variant's legibility awful and advises the black and white model.you're better often getting the simple black and white model because the legibility on this is awfulWatch from 5:57
- Teddy Baldassarre Finds some colourways, like the red dial, harder to read than the grey.the red dial for example i find is a bit harder to readWatch from 12:04
Functions are fiddly and need the manual2 of 10
- Watchfinder & Co. Needed to watch a lengthy video to relearn how to operate it.I had to watch a fifteen-minute video to remind me how to use one again.Read it in context
- Quill & Pad Functions are hard to use, requiring the manual and a video.it is not easy to useRead it in context
- Quill & Pad Hasn't used the functions since setup because they are too fiddly.I just find it all too fiddlyRead it in context
Lacks solar charging2 of 10
- JustBlueFish Watch Reviews Nitpicks the absence of solar charging, Bluetooth or radio time sync.it would be nice if the watch had some Advanced features like solar rechargingWatch from 4:49
- Just One More Watch Misses solar charging.one feature that I do miss though is solarWatch from 6:24
Resin strap is not especially soft2 of 10
- Worn & Wound Doesn't consider the strap particularly comfortable compared to good leather.I wouldn’t claim that the strap itself is particularly comfortableRead it in context
- Teddy Baldassarre Notes the resin doesn't feel particularly soft.the tactile feel of the resin compound isn't particularly soft to the touchWatch from 2:53

Show 3 more

Some details are roughly executed2 of 10
- Worn & Wound Says some features are not well executed.with some features that are actually not too well executedRead it in context
- Quill & Pad Hand edges are rough and uneven, noticeable in bright light and photos.The edges of the hands are rough and not uniformRead it in context
Sits high on the wrist1 of 10
- Teddy Baldassarre Notes thickness is where you feel it; the watch sits high on the wrist.it does sit high on the wrist so just keep that in mindWatch from 3:49
Australian pricing is poor value1 of 10
- Just One More Watch Finds the Australian price poor value.I don't think it's such a great watch at two hundred and forty dollarsWatch from 2:34
- Just One More Watch Views the Australian pricing as price gouging.I think that's a bit of a price gougeWatch from 3:03

Open a point to see who said it and jump to that moment in their review.

By aspect

PositiveMixedNegative

How reviewers judged each aspect; one square per reviewer who discussed it
Design		Praised
Dial		Mixed
Case & proportions		Praised
Wearability		Praised
Functionality		Praised
Value		Praised
Bracelet & strap		Praised
Originality		Praised
Finishing & build		Mixed
Versatility		Praised
Movement		Mostly liked

Was this consensus useful?

The reviews

10 counted, 2 more for context

Remontoir summarises; the reviewers did the work. Watch and read the originals for the full picture.

Page 29 Watches

I Wore a G-SHOCK CASIOAK For A Month, Here's What I Thought (G-SHOCK GA-2100-1AER Review)

Video, 8 minOwner's reviewAug 2025

Very positiveRecommends

A first-time G-Shock owner who wore it for several weeks finds it excellent value, praising the rugged monochrome design, dial layout, durability and features. Only minor gripes: a hard-to-read digital display, weak lume and modest battery life.

Suits: Buyers around £100/$100 wanting a durable watch for outdoors, sports or water

Disclosure: Reviewer owns it

What they said, point by point

Designpositive: Considers the rugged design visually impressive and true to G-Shock's toughness image. 1:26
Likes the matching colour across strap, case, bezel and dial as uniform and smart. 3:50
Enjoys the exposed strap screws and polished buttons as small accent details. 3:50
Dialmixed: Calls the dial layout the favourite part, with clearly legible hands and markers. 2:52
Appreciates the stepped indices and layered layout for a real sense of depth. 3:22
Finds the digital display hard to read in dim light or cloudy conditions. 6:16
Finds the lume fades quickly, making it largely redundant at night. 5:47
Case & proportionspositive: Pleasantly surprised to get mineral glass rather than acrylic at this price. 1:53
Notes the raised bezel helps protect the crystal. 1:53
Likes the screwed-down steel caseback for its sturdy look. 4:19
Wearabilitypositive: Notes it looks fairly meaty on the wrist, though less tank-like than expected. 2:23
Surprised how well it fits a skinny 17cm wrist. 2:52
Bracelet & strappositive: Finds the resin straps brilliantly integrated with solid, practical design details. 4:19
Finishing & buildpositive: Reports the crystal survived hikes and door-frame knocks without marks. 2:23
Likes the matte, smooth finish of the carbon/resin case. 2:23
Counts build quality among the reasons the watch is a winner. 7:41
Movementmixed: Considers the claimed ±15 seconds per month accuracy acceptable. 4:49
Feels the roughly three-year battery life is short compared with other Casios. 5:17
Notes the battery is easy to swap yourself. 5:17
Functionalitypositive: Considers the 200m water resistance suitable for divers and water sports. 4:49
Finds the double LED illumination very useful in the dark. 6:16
Likes the hand-shift feature for viewing the digital display. 6:44
Says setup takes getting used to but becomes intuitive after tutorials. 7:12
Valuepositive: Impressed by how much the watch offers for its price. 0:00
Advises shopping around since it is often cheaper than Casio's own site. 0:58
Would prefer a tin over the humble box, but excuses it at this price. 1:26

Watch on YouTube

Quill & Pad

Casio G-Shock GA-2100 ‘CasiOak’ Review: Is it Still Worth Buying?

ArticleOwner's reviewAug 2023Raman Kalra

Very positiveRecommends

The reviewer sees the CasiOak as more than hype: a slim, versatile, good-looking G-Shock that is arguably the best watch under $100, with minor gripes about fiddly functions, weak lume, dirt-trapping strap grooves and rough hand edges.

Suits: Buyers wanting an affordable, fun, tough daily watch, including those put off by bulky G-Shocks

Disclosure: Reviewer owns it

What the review says, point by point

Case & proportionspositive: Finds the size excellent and thinner than many watches while keeping a rugged look.
Thinks the octagonal bezel looks great.
Considers the thin case and light weight impressive.
Wearabilitypositive: Short lug-to-lug makes it feel more compact on the wrist than the numbers suggest.
Delivers the full G-Shock experience in a comfortable package.
Dialmixed: Applied indices give the dial good depth and visual interest.
Lume on the hands is disappointing.
Built-in light is adequate for reading the time but not impressive.
Designpositive: Simplified layout is less busy than other analog G-Shocks and more attractive.
Bezel text is sized to balance the watch without distracting from the face.
Originalitypositive: Appreciates that the octagonal shape comes from G-Shock's own 1980s history.
Softer octagon distinguishes it from the Royal Oak.
Enjoys the enthusiast clout and community feel of owning one.
Bracelet & strapmixed: Integrated strap design adds to the watch's appeal.
Grooves near the case are too wide or deep and collect dirt quickly.
Functionalitymixed: Was surprised by how much the watch can do.
Functions are hard to use, requiring the manual and a video.
Hasn't used the functions since setup because they are too fiddly.
Finishing & buildmixed: Hand edges are rough and uneven, noticeable in bright light and photos.
Acknowledges finishing criticism must be tempered by the very low price.
Versatilitypositive: Slips under a cuff at the office yet suits beach or hiking.
Worn far more than expected, even more than a Rolex Milgauss.
Sees it as a tough, good-looking daily wearer.
Valuepositive: Believes it is the best watch available under $100.
Affordable price, especially with frequent discounts, makes it great value and fun.
Compared with: Rolex Milgauss: Reviewer wears the CasiOak considerably more than the Milgauss.
Casio G-Shock GM-B2100 (full metal): Metal version's roughly 3x premium seems unjustified versus the resin model.
Casio G-Shock GA-B2100 (solar): Solar/Bluetooth additions are worthwhile for a modest price increase.
Audemars Piguet Royal Oak: Softer octagon keeps it from looking like just a homage.

Read on quillandpad.com

JustBlueFish Watch Reviews

Is the CASIOAK all HYPE? A Casio GA-2100 G-Shock Review

Video, 8 minHands-on reviewMay 2023

PositiveRecommends

Calls the GA-2100 an outstanding, modern G-Shock whose popularity is deserved, with solid durability and features. The reviewer faults the small negative digital display, the unlumed hour markers and its slightly large size, and still prefers the cheaper DW-5600 square.

Suits: Anyone considering adding a new G-Shock to their collection

What they said, point by point

Designpositive: Finds it very cool and modern, and a true embodiment of the G-Shock identity. 7:14
Likes the design, style and size, but not as much as the DW-5600 square. 1:28
Dialmixed: Thinks the small digital display is a cool, informative feature. 3:23
Finds the negative digital display small and hard to read except in bright light. 4:20
Notes the hands are lumed and glow in the dark. 4:49
Wishes the hour markers had lume too, while calling it a minor issue. 4:49
Case & proportionsmixed: Considers the 11.8mm thickness quite reasonable. 2:25
Notes it wears somewhat larger than the square G-Shocks. 1:55
Mineral crystal scratches easily but resists shattering, which the reviewer calls a fair trade-off. 2:53
Wearabilitypositive: Finds it lightweight, comfortable and relatively thin on the wrist. 6:15
Finds it slightly bigger than preferred on a small wrist, but still very wearable. 6:44
Prefers how the DW-5600 square feels on the wrist. 6:44
Functionalitypositive: Praises the typical G-Shock toughness and shock resistance. 1:00
Favours the 1/100th-second stopwatch as a highlight feature. ~5:46
Nitpicks the absence of solar charging, Bluetooth or radio time sync. 4:49
Dislikes relying on the backlight to read the display because it drains the battery. 4:20
Compared with: Casio G-Shock DW-5600: Prefers the square's legibility, wear and classic look, at half the price.

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Time+Tide

OUR TOP WATCH REVIEW OF 2021: The Casio G-Shock GA2100-1A ‘CasiOak’

ArticleHands-on reviewJan 2022Nick Kenyon

Very positiveRecommends

Credits the CasiOak's popularity to its tongue-in-cheek Royal Oak reference and excellent wearability. Praises the slim, comfortable case, the legible dial and the affordable price, and calls it a great first G-Shock.

Suits: First-time G-Shock buyers wanting an affordable, comfortable everyday watch

What the review says, point by point

Wearabilitypositive: Ranks it among the most comfortable G-Shocks released in recent memory.
Notes it no longer requires a large wrist to pull off, unlike many G-Shocks.
Says it wears much smaller than 45mm and fits nearly any wrist size.
Case & proportionspositive: Finds the slim profile a standout feature.
Short lugs let the case taper nicely around the wrist.
Sees the case as very thin by G-Shock standards.
Screwed caseback causes no discomfort against the wrist.
Functionalitypositive: Protected pushers remain easy to operate yet resist accidental presses.
Dialpositive: Asymmetric layout stays legible despite displaying a lot of information.
White hands and grey markers contrast well against the black dial.
Bracelet & strappositive: Finds the corrugated resin strap very comfortable.
Notes the quick-change mechanism for swapping to other colours.
Originalitypositive: Sees it as playful 'high fashion, low rent' access to a luxury aesthetic without being a straight homage.
Valuepositive: Highlights its affordability as part of its appeal.
Compared with: Audemars Piguet Royal Oak: Nickname nods to it; a very distant, tongue-in-cheek doppelgänger.

Read on timeandtidewatches.com

Watchfinder & Co.

Review: Casio G-Shock “CasiOak”

ArticleHands-on reviewDec 2021Craig Hawes

Very positiveRecommends

An affectionate essay arguing the GA-2100 is the cheapest cool watch available. The reviewer credits its appeal to Casio nostalgia, its octagonal Royal Oak-like shape, which still carries genuine Casio DNA, and above all its roughly $100 price, calling it the sweet spot.

Suits: Everyone from cash-strapped students to seasoned collectors wanting an affordable cool watch

What the review says, point by point

Designpositive: Considers the octagonal shape the second major reason for the watch's popularity.
Feels the watch is unpretentious and relaxed rather than nostalgic kitsch.
Originalitypositive: Acknowledges the watch does look somewhat like an Audemars Piguet Royal Oak.
Argues the design traces back to the F-91, with its integrated strap and eight sides.
Sees the watch's nostalgic Casio identity as something a copycat brand could never replicate.
Functionalitymixed: Finds the display and controls bewildering, but sees that as part of the authentic Casio experience.
Needed to watch a lengthy video to relearn how to operate it.
Finishing & buildmixed: Teasingly describes the plastic construction as extremely cheap, in keeping with Casio tradition.
Valuepositive: Considers the price the biggest driver of its appeal, accessible to nearly anyone.
Calls it both an everyman's watch and a genuine collector's watch.
Sees it as the sweet spot compared with pricier G-Shocks and luxury watches.
Loves that it offers comparable cool to luxury pieces for a fraction of the price.
Compared with: Audemars Piguet Royal Oak: GA-2100 resembles the Royal Oak, hence the CasiOak nickname.
Casio F-91: Shares integrated strap and eight-sided DNA, showing genuine Casio heritage.

Read on watchfinder.com

Teddy Baldassarre

A Cult Classic G-Shock with High Horology Design Elements - The G-Shock CasiOak

Video, 13 minHands-on reviewDec 2021

Very positiveRecommends

Sees the CasiOak as a standout affordable G-Shock: lightweight, compact-wearing, feature-rich, stylish thanks to its octagonal bezel, and good value at around $100. Only minor caveats are thickness, legibility on some colourways, and imperfect hand-shift function.

Suits: Anyone wanting an affordable, casual grab-and-go everyday watch; not for suits.

Disclosure: Retailer stock

What they said, point by point

Wearabilitypositive: Finds the fit compact despite large on-paper numbers, helped by light weight. 1:27
Estimates it wears like a 41–42mm round watch. 3:22
Notes thickness is where you feel it; the watch sits high on the wrist. 3:49
Bracelet & strappositive: Praises the thin, pliable resin strap as very comfortable. 2:53
Notes the resin doesn't feel particularly soft. 2:53
Finds the ventilation grooves genuinely help reduce sweating. 2:53
Thinks the resin strap suits the design cohesively and sees little reason to swap it. 3:22
Designpositive: Highlights the porthole-style bezel as the watch's appealing feature. 2:24
Bezel is more pronounced on two-tone versions; single-colour ones are more subdued. 2:24
Considers it incredibly fashionable and good looking. 11:36
Dialmixed: Finds some colourways, like the red dial, harder to read than the grey. 12:04
Considers the grey dial perhaps the most legible option. 12:04
Notes some crystal glare that doesn't really hinder reading the dial. 4:46
Case & proportionspositive: Appreciates the crystal sitting below the bezel to guard against chips and scratches. 4:46
Functionalitypositive: Finds button functions easy to identify thanks to bezel labels. 4:18
Hand-moving feature is convenient but hands reset when changing modes. 9:09
Values the range of features and toughness. 12:04
Movementpositive: Considers the module among the most reliable at this price, though basic. 11:06
Versatilitypositive: Calls it one of the most versatile all-rounders for the price. 1:54
Out of place in formal situations; advises against wearing with a suit. 12:04
Originalitypositive: Sees the analog-digital display and octagonal case as what makes it unique among G-Shocks. 11:36
Notes the bezel deliberately recalls AP and Hublot designs. 2:24
Valuepositive: Calls it good value at around a hundred dollars. 12:04
Compared with: Audemars Piguet Royal Oak: Case shape and porthole bezel have Royal Oak undertones.

Watch on YouTube

Fratello

How Does The Metal Casio G-Shock GM-2100 Compare To The Resin "Casioak" GA-2100?

ArticleComparisonSep 2021Rob Nudds

Very positiveRecommends

The reviewer was initially unconvinced but came to love the resin Casioak, praising its handsome case shape, comfort, supple strap and intuitive display. They prefer it to their square G-Shocks and Mudmasters and call it a no-brainer for Casio fans.

Suits: Long-time Casio lovers

Disclosure: Reviewer owns it

What the review says, point by point

Case & proportionspositive: Considers the case shape really handsome.
Wearabilitypositive: Prefers wearing it to their many square G-Shocks and far prefers it to Mudmasters.
Credits its size and round case for how comfortably it sits, finding it more wearable than other recent Casios.
Bracelet & strappositive: Suggests the supple strap contributes to the pleasant wearing experience.
Dialpositive: Finds the display interesting and intuitively arranged.
Designpositive: Initially resisted the Casioak as an unconvincing novelty before buying one.
Describes the resin version as looking rugged and approachable, compared with the metal one.
Originalitymixed: Notes clear Royal Oak inspiration, framed as a self-aware move to fill a gap in the market.
Compared with: Casio G-Shock GM-2100: Worlds apart; the metal version is more elegant and suited to formal or business settings.
Casio G-Shock Mudmaster: Finds the Casioak far more pleasant to wear than the hulking Mudmasters.

Read on fratellowatches.com

Just One More Watch

The Coolest Watch $99 CAN'T Buy! The 'CasiOak' GA2100

Video, 10 minHands-on reviewJan 2020

PositiveRecommends, with caveats

Calls the GA-2100 the coolest, most comfortable and best-fitting G-Shock reviewed so far, with lots of functionality for $99. Criticises the legibility of the blacked-out version and inflated Australian and grey-market pricing, and advises buying only at retail.

Suits: G-Shock buyers wanting a slimmer, lighter, comfortable G at retail price

What they said, point by point

Wearabilitypositive: Says it wears better than any G-Shock worn so far. 3:31
Finds it light despite the large 45mm diameter. 3:31
Notes it does not feel big or chunky on a 7-inch wrist. 7:22
Conforms to the wrist better than the standard 5600. 7:50
Dialmixed: Finds the blacked-out version not very legible. 7:22
Colour contrast between hands and dial still allows a reasonable read. 7:22
Notes the lack of an anti-reflective coating on the plastic crystal. 7:50
Finds the hand lume stronger than on other ana-digi Casios owned. 5:25
Case & proportionsmixed: Doubts the carbon core guard protects better than older resin cases. 4:28
Enjoys having some carbon on the wrist at this price. 4:28
Bracelet & strappositive: Finds the resin band considerably softer than the one on the 5600. 8:19
Welcomes quick-release spring bars as a G-Shock first. 4:56
Functionalitypositive: Praises the large amount of functionality compared with basic G-Shocks. 8:19
Likes the hand-shift feature that moves the hands clear of the digital display. 5:55
Misses solar charging. 6:24
Does not mind the lack of Bluetooth, considering it a gimmick. 6:24
Designpositive: Considers the watch crushingly cool despite the legibility issues. 1:08
Says it looks great and wears fantastically. 9:17
Originalitymixed: Thinks the 'CasiOak' nickname is more catchy than an accurate comparison. 4:56
Valuemixed: Considers it one of the best G-Shocks available at its $99 price. 8:19
Finds the Australian price poor value. 2:34
Views the Australian pricing as price gouging. 3:03
Would not pay over retail and advises waiting for the hype to die down. 9:17
Compared with: Casio G-Shock DW-5600: GA-2100 wears better, conforms more, has a softer band and more features.

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Worn & Wound

Review: G-Shock GA-2100-4A

ArticleOwner's reviewNov 2019Zach Kazan

PositiveRecommends, with caveats

A fun, bold, remarkably thin and comfortable G-Shock at a low price, recommended purely as a design object rather than a tool. The tiny LCD is a real weakness and some features are poorly executed, but the reviewer doesn't mind.

Suits: Collectors wanting an affordable, fun break from their usual watches

Disclosure: Reviewer owns it

What the review says, point by point

Case & proportionspositive: Considers it one of the slimmest G-Shocks, a key reason for its appeal.
Notes it is large but notably smaller than many ~50mm G-Shocks with awkward geometry.
Sees the Carbon Core Guard construction as critical to the case's appeal and promising for the future.
Wearabilitypositive: Finds it remarkably comfortable compared with bulky G-Shocks.
Narrow top and bottom make it feel small at sensitive parts of the wrist, like an oval watch.
Lighter and easier to wear yet still feels robust.
Dialmixed: Raised indices add depth and legibility.
Feels the lume on the hands could be stronger.
The LCD is nearly unreadable without backlight unless in direct sunlight.
Likes the backlight.
Functionalitynegative: Screen is too small to clearly show timer or timezone information.
Treats it as a time-only G-Shock and doesn't view it as a tool watch.
Recommends it only as a design object, not as a tactical tool.
Designpositive: Appreciates how dial, case and strap blend into a single cohesive object.
Prefers the red version, finding the black less fun and vibrant.
Finds it bold and brash, with some of the early Royal Oak spirit.
Bracelet & strapmixed: Thinner strap than standard G-Shocks makes it more wearable.
Doesn't consider the strap particularly comfortable compared to good leather.
Finishing & buildnegative: Says some features are not well executed.
Versatilitymixed: Thin enough to slip under a shirt cuff.
Sees it as a weekend fun watch rather than a daily wearer.
Valuepositive: Considers it an affordable small luxury.
Compared with: Audemars Piguet Royal Oak: Not a true substitute; the Royal Oak is far better finished, though spirit is shared.
Patek Philippe Ellipse: Wears similarly to an oval watch like the Ellipse.

Read on wornandwound.com

Watch Geek

GA-2100 G-Shock review - a tough Royal Oak - GA2100

Video, 8 minHands-on reviewNov 2019

Very positiveRecommends

The reviewer calls the GA-2100 one of the best-looking G-Shocks since the original square, praising its serious, simple design, compact dimensions and comfort. The only complaint is poor legibility on the blacked-out variant, so the black and white model is recommended instead.

Suits: People wanting a simpler, more serious, less toy-like G-Shock

Disclosure: Reviewer owns it

What they said, point by point

Designpositive: Ranks it among the best-looking G-Shocks since the original square. 1:14
Finds it looks more serious than other G-Shocks while keeping G-Shock identity. 2:39
Welcomes the simpler, less toy-like approach versus chunky modern G-Shocks. 2:10
Dialmixed: Judges the stealth variant's legibility awful and advises the black and white model. 5:57
Notes the 3D markers give enough shadow contrast to read in daylight. 5:57
Finds the LED backlight good for the digital display but useless for the analog hands. 6:25
Case & proportionspositive: Loves the case dimensions. 3:35
Glad Casio is following the trend back to normal watch sizes. 3:07
Notes the short lug-to-lug offsets the 45mm width. 3:35
Wearabilitypositive: Finds it wears very comfortably, helped by low weight and thinness. 4:03
Says it wears much like the small square G-Shock despite its width. 3:35
Functionalitypositive: Notes the module is basic, lacking solar, radio sync, GPS or Bluetooth. 0:47
Values that it keeps full G-Shock shock resistance and water resistance. 4:59
Originalitypositive: Appreciates the return to the square's functional design formula. 2:10
Acknowledges the Royal Oak resemblance but sees nothing wrong with it. 3:07
Valuepositive: Considers the $99 price affordable and low-risk. 7:24
Notes strong demand makes it easy to flip if unwanted. 7:24
Compared with: Casio G-Shock DW-5600 (square): Wears much like the square; slightly wider but shorter lug-to-lug.
Casio G-Shock G-056: G-056 was even thinner at 11mm; reviewer calls it great.
Casio G-Shock Mudmaster: GA-2100 is simpler and less chunky than recent huge G-Shocks.
Audemars Piguet Royal Oak: Octagonal look earns it the 'Casio Royal Oak' nickname.

Watch on YouTube

Also covered by

Teddy Baldassarre

G-Shock CasiOak In 2025

ArticleGuide or roundupJun 2025Mark Bernardo

Positive

Presents the GA2100 as an affordable, surprisingly slim G-Shock whose octagonal look appeals to luxury-watch fans. Its information-rich analog-digital display and 200m water resistance still satisfy core G-Shock enthusiasts.

Suits: Budget-minded fans of the Royal Oak look and core G-Shock enthusiasts

Not a review of the watch in hand (news, a guide or a reaction), so it isn't counted.

What the review says, point by point

Case & proportionspositive: Finds the thickness surprisingly modest given G-Shock's reputation for chunkiness.
Sees the relative thinness as a draw for luxury-watch fans who prefer slimmer profiles.
Designpositive: Notes the integrated case-and-strap design and mainly analog dial won over many mechanical-watch purists.
Functionalitypositive: Values the information-rich analog-digital layout for core G-Shock fans.
Considers the 200m water resistance impressive.
Notes the LED light makes the dial easy to read at night.
Calls the hand-shift function, which moves the hands off the digital display, useful.
Originalitymixed: Views the watch as evocative of the Royal Oak but not a faithful copy, lacking key elements like screws.
Valuepositive: Emphasises that almost any enthusiast can afford it at around $100.
Expects the entry model to remain affordable even as the family moves upmarket.
Compared with: Audemars Piguet Royal Oak: Octagonal bezel evokes the Royal Oak, though it is not a direct homage.
Tissot PRX: PRX costs hundreds; the G-Shock offers the look at mass-market pricing.

Read on teddybaldassarre.com

Watchfinder & Co.

$100 G-Shock “CasiOak” is the Cheapest Cool Watch You Can Buy

Video, 8 minHands-on reviewDec 2021

Very positiveRecommends

An essay-style celebration of the GA-2100 as the cheapest cool watch available, praised for its Casio nostalgia, its Royal Oak-like octagonal shape that still feels authentically Casio, and its unpretentious low price that bypasses luxury-market gatekeeping.

Suits: Everyone from students to seasoned collectors wanting an affordable, cool watch

Another review by this creator is counted instead: one vote per creator.

What they said, point by point

Valuepositive: Considers the price accessible to nearly anyone, making it a true everyman's watch. 5:19
Calls it the sweet spot compared with pricier mid-level G-Shocks. 6:17
Loves that something this cool costs a fraction of gatekept luxury watches. 6:47
Originalitypositive: Notes the octagonal shape clearly resembles a Royal Oak, fuelling its popularity. 3:48
Argues the integrated strap and eight sides trace back to Casio's own F91 DNA. 4:46
Feels it is authentically Casio rather than a copy. 4:46
Believes its nostalgic Casio identity is something a copycat brand couldn't replicate. 1:00
Designpositive: Describes it as cool and nostalgic, fitting the current 70s/80s revival. 4:46
Appreciates that it doesn't feel try-hard or schmaltzy. 6:17
Functionalitymixed: Describes the display and controls as bewildering, in keeping with Casio tradition. 1:57
Needed to watch a long video to relearn how to operate it. 2:24
Compared with: Audemars Piguet Royal Oak: GA-2100 looks a bit like the Royal Oak, earning the CasiOak nickname.
Casio F-91W: GA-2100 shares the F91's integrated strap and eight-sided DNA.

Watch on YouTube

Specifications

Reference: GA-2100-1A1
Case: 45.4mm, carbon / resin (Carbon Core Guard)
Thickness: 11.8mm
Lug to lug: 48.5mm
Movement: Casio module 5611 (analog-digital quartz) (quartz)
Water resistance: 200m
Crystal: mineral glass
Bracelet or strap: resin strap
Announced: November 2019
List price (US): $99Launch price USD 99 (2019).

Creator Consensus is built only from what reviewers said. Prices, retailers and any commercial relationship never affect it. How consensus works