Interval Timer

A configurable interval timer for workouts or focused work. Set preparation, work, rest, rounds and an optional cool-down, then follow colour-coded phases with round counts, remaining time and total session time, and copy a summary at the end.

Date & Time Runs client-side Free to use

Jump to the tool

About the Interval Timer

Interval Timer runs a session of repeated work and rest periods. Set a preparation countdown, the work and rest durations, the number of rounds and an optional cool-down. Durations can be typed as seconds (90), minutes and seconds (1:30) or hours, minutes and seconds. Rest is not added after the final round, and a whole session can last up to 12 hours.

While it runs, a clearly labelled, colour-coded panel shows the current phase, the round, the time left in the phase, the total time left in the session and what comes next. You can pause, resume, skip a phase, stop early or restart the session. An optional beep is off by default and only turns on when you tick it; if the browser blocks sound, the tool says so. Browsers throttle background tabs and may stop timers and sound when the device is locked, so keep the page visible. Unlike a Pomodoro timer, it is built for any number of short, repeated rounds.

How to use

Enter preparation, work, rest, rounds and cool-down.
Optionally tick the beep option (it is off by default).
Press Start and follow the phase panel.
Use Pause, Resume, Skip Phase, Stop or Restart Session as needed.
Copy or download the summary when the session ends.

Key features

Preparation, work, rest, rounds and optional cool-down.
Phase name, round, phase time left and session time left.
Colour-coded phases that always include a text label.
Pause, Resume, Skip Phase, Stop, Restart Session and Reset.
Optional beep, off by default, with a message if sound is blocked.
Session summary with phase history to copy or download.
Catches up correctly after the tab was hidden.

Best practices

Keep the page open and visible while the session runs.
Test the sound before you start if you rely on it.
Start with fewer rounds and build up gradually.
Use the preparation phase to get into position.
Seek qualified advice before starting a new exercise programme.

Benefits

Hands-free structure for repeated intervals.
Clear, readable phases from across the room.
Flexible settings for many routines.
Private: nothing is uploaded or stored.

Frequently asked questions

How do I enter durations?

Type seconds (45), minutes and seconds (1:30) or hours, minutes and seconds (1:00:00). Preparation, rest and cool-down can be 0 to skip them; work must be at least 1 second.

Is there a rest after the last round?

No. Rest periods come between rounds, so the session moves straight from the final work period to the cool-down (if set) or the end.

Why didn’t I hear a beep?

Sound is off by default. Tick the beep option to turn it on; browsers only allow sound after you interact with the page. Some browsers or settings block it entirely, and sound may not play in a background tab or on a locked device.

Will the timer keep working if I switch tabs?

It keeps track of time and catches up when you return, but browsers throttle background tabs, so phase changes, the display and sound may be delayed while the tab is hidden. Keep the page visible for the best results.

What does Skip Phase do?

It ends the current phase immediately and starts the next one. Skipped phases are marked in the session summary.

What is the difference between Stop, Restart Session and Reset?

Stop ends the session early and shows the summary. Restart Session starts again from the beginning with the current settings. Reset stops everything and restores the default settings.

Is anything saved or sent anywhere?

No. Everything runs in your browser. Times, laps, shifts, events and dates are not uploaded and are not saved in browser storage. Reset clears them, and closing the page discards them.