W-738H a £45 square digital that buzzes instead of beeps

What is new about the Casio W-738H?

The W-738H is a new square-faced digital from the Casio Collection range, released in the UK in May 2026 at an RRP of £45. Japan got it the same month at 7,700 yen, mainland Europe followed in June at €49.90 and the US at $54.95. The UK range covers the W-738H-1AV in black with a silver-tone bezel and the W-738H-3AV in khaki.

The headline is the vibration alarm. Until now, most Casios that buzz on the wrist have been G-Shocks, with the price and bulk that comes with them, or the round W-736H and rectangular W-735H. The W-738H puts the same idea into a slimmer square case. Hold the start button for two seconds in timekeeping mode and every alert switches to vibration: the alarm, the countdown timer, the stopwatch and the hourly signal, with button tones muted too.

Casio has also thought about the details that make vibration actually work. The band has a shorter hole pitch than usual, so you can set it closer to the wrist and feel the buzz. The start and vibration button has its own shape and an accent colour so you can find it by touch, and the centre light button sits proud enough to press on the move.

How big is it, and how will it wear?

Casio quotes the case at 47.0 x 42.8 x 13.4 mm, and Notebookcheck reports a weight of 43 g. The 47 mm figure is the length from the top of the case to the bottom, which is the number that decides whether a watch overhangs a small wrist. At 42.8 mm across it is a mid-size square, not a mini.

For context, a typical wrist of around 16 to 18 cm should take a 47 mm length comfortably. Wrists under 15 cm may find the square corners reach the edges, which is worth checking against a watch you already own. At 13.4 mm thick it is not slim in absolute terms, but it is thinner than most vibration-equipped digitals, and the light resin build means it should be easy to forget under a cuff.

How accurate is it, and how long does the battery last?

This is a quartz watch, and Casio rates accuracy at plus or minus 30 seconds a month, which is ordinary for a budget digital. It does not set itself by radio or Bluetooth, so expect to correct it every few months and at each clock change.

The battery is a CR2032 cell that Casio says should last around ten years. That figure assumes modest use, roughly one backlight press and one alarm a day, so heavy use of the vibration motor will shorten it. Functions include dual time, a 1/100-second stopwatch, a 24-hour countdown timer, a daily alarm, an hourly time signal and a full auto calendar to 2099.

Is it tough enough for swimming and daily knocks?

Water resistance is 100 m, which covers swimming and snorkelling without worry. The LED backlight is bright and easy to trigger. What it does not have is G-Shock shock resistance, so it is built for everyday wear rather than for being dropped on concrete or worn on a building site.

How does it compare with the G-Shock DW-5900U?

The nearest rival in Casio's own catalogue is the G-Shock DW-5900U-1, released in the UK in January 2026 at £80 RRP. For the extra £35 you get 200 m water resistance, full shock resistance, world time and accuracy quoted at 15 seconds a month, also with a ten-year battery. Its published feature list does not include a vibration alarm, though, and it comes in a chunkier G-Shock case. If silent alerts matter more to you than toughness, the W-738H is the better fit and the cheaper one.

Against the older W-736H, the choice mostly comes down to face shape: round versus square, with the newer model adding the shorter band pitch and the reshaped vibration button.

What is the catch?

It is a tool watch with nothing smart about it. There is no Bluetooth time sync, no solar charging, no step counter and no world time beyond the second time zone. The case is resin, and Casio's release material does not name the crystal material, so do not expect sapphire-style scratch resistance. And as with any vibration watch, the buzz is only useful if you wear the band snug.

Who should buy it?

Teachers, nurses, shift workers, students sitting exams and anyone in an open-plan office who wants a wrist alarm that will not disturb the room. It is also an easy recommendation as a swim and holiday watch at £45 RRP. If you want a watch that tracks your activity or sets its own time, look elsewhere.

“A silent alarm used to mean buying a G-Shock. The W-738H does it for £45 in a case you can wear to the office.”

What do owners say?

Themes from public owner feedback, paraphrased. We never copy Amazon reviews or ratings.

• Early enthusiast reaction, including discussion on r/casio summarised by The Gadgeteer, centres on the value of getting a vibration alarm, 100 m water resistance and a ten-year battery together at this price.

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