Interval Timer
← All toolsSet a work length, a rest length and a number of rounds, and clocklab alternates them automatically with a chime at every switch — a 5-second get-ready countdown gives you time to get into position before round one. The dots above the dial track exactly which round you're on.
Interval Timer
Idle
00:20
Work
Screen kept awake while this runs
Starts with a 5-second get-ready countdown, then alternates work and rest. Keeps running in a background tab and picks itself back up if you reload.
How to use the Interval Timer
- Set Work and Rest lengths in seconds, and how many Rounds to run.
- Tap Start — a 5-second get-ready countdown runs first, then work and rest alternate automatically with a chime at each switch.
- Watch the round dots: filled dots are completed rounds, the glowing dot is the round in progress.
- When the last round's work phase ends, the display reads Done — tap Start again (now labelled Restart) to run it again.
FAQ
- What's the get-ready countdown for?
- A fixed 5-second buffer after you tap Start, before round one's work phase begins — enough time to get off your phone and into position.
- Does Rest count as part of the round?
- Yes — each round is one Work phase followed by one Rest phase (except the very last round, which ends after Work with no trailing rest).
- Can I pause mid-round?
- Yes — Pause holds the exact remaining time in the current phase; Start resumes it from exactly there.
- How is this different from the Pomodoro Timer?
- Pomodoro is built around longer focus/break cycles (minutes) with a long-break rhythm for deep work; the Interval Timer is built around short work/rest bursts (seconds) for a fixed number of rounds — classic HIIT structure.
- Will the screen stay on through the workout?
- Tap Room mode before you start. It fills the screen with the round clock and the work/rest phase and asks the browser for a screen wake lock, so the phone does not dim and lock between rounds. The lock is dropped as soon as you pause, reset, or the last round finishes — a gym phone lit until the battery dies is a worse problem than the one being fixed. Where the browser has no wake lock API the button still works; it just cannot stop the device sleeping on its own.
- What if I lock my phone or switch apps mid-workout?
- The rounds are driven by a Web Worker reading the real clock, so the timer keeps advancing rather than freezing when the tab goes to the background, and it picks up mid-workout if the page reloads. Tick “Notify me at every round change” to get a system notification at each switch — useful when the screen is off.
