CheckMag | Easter eggs on your wrist: Secret features hidden in Casio watches
Everybody loves a good secret, and Casio’s humble digital watches have a few up their sleeves. From hidden diagnostic modes to surprise display tricks, these “Easter eggs” can turn ordinary wristwatches into conversation pieces. As with any Easter eggs, they’re not obvious features - you’d never know they exist unless you press the right combination of buttons. Let's take a look at some secret features tucked away in popular Casio models.
Messages in classic Casios
One of the most famous Casio Easter eggs hides in plain sight on the F-91W and its siblings. If you hold down a certain button (spoiler alert, it's the lower-right button), the display will briefly spell out “Casio” using the LCD segments. This hidden screen was presumably designed as an authenticity check. The vintage A158WA (which shares the F-91W’s module) also does this trick, as does the newer W-217H, which is actually pretty cool, considering even Casio’s cheapest models aren’t above an Easter egg. In fact, Casio fans and collectors once used this as a way to spot fakes - though counterfeiters eventually caught on.
The “Casio Royale” Diagnostic Mode
The popular world-time AE-1200 - nicknamed “Casio Royale” by fans - also conceals a hidden function. Press and hold a certain trio of buttons (in this case, both buttons on the left and the lower-right button together) and the watch enters a diagnostic display test. All the segments on its screen light up at once, often followed by a code number. If you're thinking this is just for show, it’s actually an LCD test that confirms all parts of the display work properly. You can use it to verify a genuine module (a fake might not replicate the sequence correctly). It’s a fun party trick to see your AE-1200’s world map and numerals all glow in unison - before you snap back to normal timekeeping.
G-Shock “Check Engine” screens
Casio’s G-Shock line - especially the classic square models - has its own set of quirks. Many G-Shocks with advanced features like a tilt sensor (for auto backlight) or solar power have special diagnostic modes accessible via three-button combinations. For example, on a GW-M5610 or GW-5000 (solar-powered G-Shock squares), one hidden combo will flash all LCD segments in a test pattern, while another brings up a readout for the solar charging level (displaying “8888” when light is detected). Yet another screen might show a confusing code of letters and numbers, which is essentially the watch checking its internal systems. This is just an utterly simplified form of a car’s “check engine” diagnostics. Of course, they’re not features you’d use daily, but it’s seriously cool to know that G-Shocks can perform a self-test.
Backlight quirks
Not all Easter eggs are in the digits; some hide in the glow. Over the years, Casio has released multiple limited-edition models where a special image or logo appears when you press the backlight. In collaboration models, a company logo or character might be printed invisibly on the dial, only revealed by the electroluminescent (EL) backlight. For instance, one Bodega x G-Shock edition displays a world map outline glowing red against the green EL glow.
Casio’s hidden features aren’t limited to visuals, either. Some models hide extra functions that aren’t obvious at first glance. For example, the DW-5600 has a little-known auto-repeat feature for its countdown timer (you can toggle it by holding a button in Timer mode). It’s a useful function, but you’d never know it was there without diving into the manual or online forums. All these quirks add an extra layer of charm to Casio's timepieces. Because sometimes, it’s not the features you use every day that make a watch memorable. It’s the ones you stumble across when you weren’t even looking.
Source(s)
Reddit, Fratello Watches, 60 Clicks
