Set the timer to 27 seconds

How to use the online timer

Interval sprints live or die on accurate timing, and 27 seconds is a common burst length whether you're doing suicides on the court or sprint efforts on the footpath. Tap start right before you take off, and let the sound tell you when to ease up instead of glancing at your watch mid-stride. It keeps every rep honest and stops the last few seconds turning into a guess.

It runs the moment you hit Start, no extra steps needed before the numbers begin moving. Because everything happens inside this browser tab, it needs to remain open while the clock runs; switching tabs is fine, but closing the page or turning off your screen partway through will stop the countdown. A sound marks the finish, so you'll know the moment it's done without having to watch it count down.

There's something to be said for a timer that doesn't try to sell you a premium version or bury the start button behind ads you have to swipe past. This one lives in a browser tab, plain and straightforward, doing exactly what it says and nothing else. You can leave the tab minimised while you get on with things, and it'll keep counting until it's time to let you know. If you would rather say put a timer on for 27 seconds, that works too — press Start and the page does the rest.