Classroom Timer & Stopwatch

Start in one tap

Each length below opens on its own page with the time already set, so there is nothing to type in front of a class. Bookmark the two or three you use every day.

Any other length: set hours, minutes and seconds on the timer page.

On the projector

Both tools have a full-screen mode, which is the point at which a timer becomes readable from the back of a room: the digits fill the display and everything else gets out of the way. The countdown also appears in the browser tab title, so a teacher watching a laptop can see the time left without switching tabs.

The alarm clock is the one to use for a fixed moment rather than a duration — the end of a test, the start of an assembly — and its full-screen bedside mode doubles as a classroom wall clock.

Keyboard control, so you're not hunting for a button

The multi-timer board on the main timer page is click-only — the shortcuts are on the single-duration pages, which is where you want them mid-lesson anyway.

Transitions, rotations and routines

The timer runs up to three countdowns at once, each with its own label and its own alarm sound. That is enough for a three-station rotation where every group is on a different clock, and the different sounds mean a group knows their time is up without looking.

Common uses that map straight onto the presets above: a two-minute tidy-up, a five-minute warm-up, a ten-minute station, fifteen minutes of silent reading. There is also a study timer for longer focus blocks.

Reading fluency, repeated timings and experiments

This is what the stopwatch's lap button is for. Tap Lap at the end of each reader, each attempt or each trial, and you get a numbered list where every row shows two things: the lap time (how long that one took) and the total (elapsed time since you started). The fastest lap is highlighted green, the slowest red, and the fastest, slowest and average are shown above the list.

For repeated-trial work — a pendulum, a reaction test, a timed run — that means one session gives you every trial and the spread, without stopping and restarting between them.

Sharing what you measured

A measurement nobody can keep isn't much use in a classroom, so the stopwatch lets a session leave the page three ways:

The CSV is the one for records: a row per lap, with the lap time and the running total, ready to paste into a tracking sheet or chart across a term. The image is the one for people — it shows the total time, the fastest, slowest and average lap and the full lap table in one picture, which is what you want to hand a student, drop into a report, or send to a colleague or a parent.

Nothing is uploaded. The session — including a stopwatch still running — is stored on that computer, so it survives a refresh, and the CSV and the image are made in the browser.

What a browser timer can't do

Worth knowing before a lesson depends on it:

• It rings only while the page is open. The tab can be in the background and the window can be behind another, but if the tab is closed or the machine sleeps, no alarm.
• A background tab may be updated less often by the browser, so a display that isn't on screen can lag.
• The precision you see depends on the device and browser. Good for everyday use — not for official sports timing, scientific measurement or anything medical.
• Sound needs the device's volume up and, on some browsers, one tap on the page first before audio is allowed to play. Test it once on the classroom machine.

The full browser limitations page explains why, and how it works covers the timing itself.

Accessibility — what to check

Stated plainly, because a classroom is exactly where this matters:

• The big read-out is drawn as segments rather than text, so it also carries a text version for screen readers. It is deliberately not announced on every tick — a display that spoke every second would be unusable — which means a screen-reader user gets the value on demand, not a live countdown.
• The alarm is sound only. There is no flash or vibration, so for a deaf or hard-of-hearing student pair it with something visual: the full-screen display on the projector changes at zero.
• Every control is a real button and reachable by keyboard, and the shortcuts above work without a mouse.
• The display colour can be changed on the alarm clock and the timer if the default is hard to read on your projector.