Casio Watch Model Number Lookup
Casio does not build a date into its model numbers — it builds the line into them. The letters at the front tell you whether you are holding a G-Shock, an Edifice chronograph, a Pro Trek, a Baby-G or a classic F-91W, and they hint at whether it is solar, radio-controlled or plain quartz. Type any model below to decode the prefix instantly, then read on for the full family map and how to find your module number.
Casio Model Number Decoder
Type the model number from your caseback or box — case and hyphens do not matter. The decoder reads the letter prefix and tells you the line and its likely features.
The prefix identifies the line, not every spec. For the exact functions and the right manual, read the 3–4 digit module number on the caseback and use our G-Shock module number lookup.
Casio has sold tens of thousands of references across dozens of ranges, and unlike a Rolex reference or a Seiko serial, a Casio model number is not a date or a value stamp — it is a shorthand for the collection and the headline technology. Once you can read the letter prefix, an unfamiliar code like GWG-2000 or ECB-30 stops being a random string and becomes “a solar-radio Mudmaster” or “a Bluetooth Edifice.” This guide gives you the decoder above, an annotated breakdown of how a Casio code is built, a map of every major line, and the one number you actually need to open the manual.
Anatomy of a Casio model code
The line prefix is the part the decoder above keys on. The modifier letters that sometimes sit between the prefix and the number carry real meaning: B usually signals Bluetooth smartphone-link, M a metal case or bezel, S a slimmer or solar variant, and W radio (WaveCeptor) sync. The series number groups a case shape or size — the 5600 and 5000 are the classic square, the 2100 the octagonal “CasiOak” — while the trailing digits and letters after the hyphen are just colour and strap codes. None of it encodes a production date.
The Casio family map
Casio groups its watches into a handful of brands, each with its own prefixes. Here is what the letters point to:
G-SHOCK — shock-resistant tough watches
- DW — digital G-Shock, no solar or radio (the original format, e.g. DW-5600).
- GA / GMA — analog-digital G-Shock; the “A” is analog. Battery quartz (e.g. GA-2100 “CasiOak”).
- GW / GWM — Tough Solar and Multi-Band 6 radio sync (e.g. GW-M5610, GW-5000).
- GMW — full-metal square, solar + radio + often Bluetooth (e.g. GMW-B5000).
- GM — metal-bezel over resin (e.g. GM-2100, GM-5600); usually battery quartz.
- GG / GWG — Mudmaster / Mudman, mud-resistant Master of G; GWG adds solar + radio.
- GWF — Frogman, the ISO dive Master of G.
- GBD / GBA — G-SQUAD Bluetooth fitness models with step and activity tracking.
Premium metal G-Shock
- GST — G-STEEL, slimmer layered analog-digital, usually Tough Solar.
- MTG — MT-G (“Metal Twisted G”), carbon and metal core, solar + radio or Bluetooth.
- MRG — MR-G (“Mr. G”), the top tier: titanium, hand-finished, GPS/Bluetooth + solar.
- MSG — G-MS, the metal-accented women’s G-Shock.
Other Casio brands
- BG / BGD / BGA / BA — BABY-G, the compact shock-resistant line.
- EF / EFR / EFV / EFB / ECB / EQB / EQS — EDIFICE, motorsport-styled metal chronographs; EQ/ECB variants add Tough Solar and Bluetooth.
- PRG / PRW / PAG / PAW — PRO TREK, outdoor triple-sensor watches; PRW/PAW add solar + radio.
- OCW — OCEANUS, the Japan-market luxury line: titanium, sapphire, solar + radio.
- LCW — LINEAGE, slim solar-radio dress watches.
- MTP / MTD / MDV — Casio’s standard analog quartz dress and diver-style watches (e.g. MTP-1374, MDV-106 “Duro”).
- LTP / LRW / SHE — women’s analog quartz; SHE is the dressy Sheen line.
- F / A / W / AE / CA — the vintage and casual digitals: F-91W, A158/A168 steel, W-series sport, AE world-time, CA calculator watch.
Casio periodically reuses and revises prefixes, and modifier letters can add or remove features, so treat this as the line map — not a promise about every individual reference.
Verify your watch is genuine — first scan free
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Find your module number for the exact spec
The model number tells you the family. The module number — a separate 3 or 4 digit code such as 3229, 5611 or 3495 stamped on the caseback — identifies the actual movement inside and its exact functions. It matters for two reasons: several different models can share one module, and Casio organises its instruction manuals by module number, not by model. If you want to set world time, reset the alarm, or confirm whether your watch really is solar, the module number is what you look up.
It usually sits close to the model number on the caseback, printed smaller. On a resin G-Shock the text can be tiny, so a macro photo under good light helps. Once you have it, our sibling tool does the rest.
Have the caseback module code already? Go straight to the G-Shock module number lookup to identify the movement, its features, and the correct Casio manual.
What the model number can and can’t tell you
Be honest with what the prefix delivers. It reliably tells you the line and gives a strong hint at the headline technology. It does not tell you the production date, the exact water-resistance rating, or — on its own — guarantee a specific feature, because Casio revises features within a prefix over time and modifier letters shift the spec. A plain GA is battery quartz, but a GA-B gains Bluetooth and solar. When precision matters, the module number is the source of truth.
Using the model number to spot a fake
Counterfeit G-Shocks and Baby-Gs are common, and the caseback codes are a useful tell. Watch for these:
- ✖Model and module don’t belong together. If the model number implies a solar-radio watch but the module is a plain digital movement (or the module is missing entirely), be suspicious.
- ✖A prefix that doesn’t exist. Fakes sometimes invent codes. If the decoder above cannot place the prefix in any line, cross-check it on Casio’s own site.
- ✖Sloppy caseback printing. Genuine Casio caseback text is crisp and evenly spaced. Blurry, misaligned or misspelled markings are a red flag.
- ✖The watch doesn’t match its line. A code that decodes to an analog-digital model on a purely digital watch (or vice versa) means the case, dial and movement don’t agree.
Common Casio model number questions
How do I read a Casio watch model number?
A Casio model number is a letter prefix followed by a series number, for example GA-2100 or DW-5600. The letters identify the line and its core technology: DW is a digital G-Shock, GA is an analog-digital G-Shock, GW adds Tough Solar and Multi-Band 6 radio sync, EFR is an Edifice chronograph, PRW is a Pro Trek with sensors, and BGD is a Baby-G. Optional letters between the prefix and the number are feature modifiers (B for Bluetooth, M for metal). The digits are the series and a color code, not a spec. The prefix tells you the line, not every feature, so confirm the exact specification with the module number on the caseback.
What is the difference between a Casio model number and a module number?
The model number (for example GW-M5610) is printed on the caseback and on the box, and it identifies the watch you can buy. The module number is a separate 3 or 4 digit code (for example 3495) also stamped on the caseback that identifies the internal movement and its exact functions. Two different models can share one module, and Casio organizes its instruction manuals by module number, not model number. Use the model number to identify the line and the module number to find the correct manual and precise operating instructions.
Does the Casio model prefix tell me if my watch is solar or radio-controlled?
It strongly hints at it but is not a guarantee. GW, GMW, GWG, PRW, PAW, OCW and MRG models are Tough Solar and usually add Multi-Band 6 radio time sync. GA, DW, GM and most Edifice and dress models are ordinary battery quartz with no solar or radio. Feature-modifier letters change things too, so a GA with a B is Bluetooth. Because the same prefix can span several feature sets over the years, the only certain way to confirm solar, radio or Bluetooth is to look up the module number for your specific watch.
Where is the model number on a Casio watch?
The model number is engraved or printed on the caseback, usually as the largest code, and it is also on the original box, the warranty card and the retail tag. On the caseback you will typically see the model number, the smaller 3 or 4 digit module number, water-resistance markings and the country of manufacture. On some resin G-Shock models the caseback text is small, so a macro photo under good light makes it far easier to read.
What does the GA in GA-2100 stand for?
In GA-2100 the A stands for analog. GA denotes a large-format analog-digital G-Shock with hands over a digital sub-display. The GA-2100, nicknamed the CasiOak for its octagonal bezel, is a battery-powered quartz G-Shock with no solar charging or radio sync in its base form. Later variants add modifiers, for example GA-B2100 gains Bluetooth and Tough Solar, which is why the extra letter matters when you decode the model.
How do I find the manual for my Casio watch?
Casio publishes its instruction manuals by module number rather than model number. Read the 3 or 4 digit module number from the caseback, then look it up to open the correct manual. This model number decoder identifies the line and likely features, and our companion G-Shock module number lookup tool takes the caseback module code and points you to the exact manual and feature list.
Important Note
The prefix decoder identifies the line and likely technology, not every specification of an individual reference. Casio revises features within a prefix over time, so confirm exact functions with the module number and Casio’s own listing. For a high-value metal G-Shock (MT-G, MR-G) or any purchase where authenticity matters, an in-person inspection by a certified watchmaker is always the gold standard.