Free Interval Timer
HIIT and circuit timer with work/rest rounds.
What is the Interval Timer?
Interval workouts live and die by the timer. When you're mid-burpee you can't be squinting at a clock or tapping your phone — you need clear audio cues telling you when to push and when to breathe. This interval timer does exactly that: set your work, rest and rounds, press start, and follow the beeps.
It runs entirely in your browser, with a big colour-coded display and a tone on every switch, so you can keep your eyes off the screen.
Last updated: Aug 27, 2026
What does this tool do?
You set four things — a prep countdown, the work interval, the rest interval and the number of rounds — and the timer runs the whole session. The screen turns to show whether you're working or resting, a tone sounds at each change, and the final seconds of every interval beep so a switch never catches you off guard.
It's ideal for HIIT, Tabata and circuit training, and it shows your total workout length before you start.
Key features
Work / rest / rounds
Fully customisable intervals.
Prep countdown
A few seconds to get into position.
Audio cues
A tone at every switch, plus a countdown beep.
Colour-coded
The display shows work vs rest at a glance.
Runs in-browser
No app, nothing to install.
Example
Common use cases
- HIIT fans — Run high-intensity intervals hands-free.
- Tabata trainers — Dial in 20/10 × 8 in seconds.
- Home workouts — Structure a circuit without equipment.
- Runners — Time sprint-and-jog intervals.
- Coaches — Run a class through timed stations.
- Stretching / mobility — Hold poses for set intervals.
Benefits
- Keep your eyes off the screen — the beeps guide you.
- See your total workout length before you start.
- Colour changes make work vs rest obvious.
- Free and installs nothing.
Tips
- For classic Tabata use 20s work, 10s rest and 8 rounds; adjust as you get fitter.
- Set a prep countdown of 5–10 seconds so you can get into position before round one.
- Turn your volume up and keep the tab active — background tabs can throttle timers and audio.
- Rest is a real part of the session; resist cutting it short so each work interval stays high-quality.
- Prop your phone where you can hear it rather than see it, and let the tones run the workout.
Common mistakes to avoid
Skipping the prep time
Fix: A short prep countdown stops round one starting before you're ready.
Locking the phone mid-session
Fix: Keep the tab active and the screen awake so the timer and sound keep running.
Cutting rest short
Fix: Rest keeps work intervals intense — take the full recovery the timer gives you.
Muting the device
Fix: The cues are audio; turn the sound on so you don't have to watch the screen.
How it works
- 1
Set your intervals
Prep, work, rest and number of rounds.
- 2
Press start
It counts down each phase with cues.
- 3
Follow the beeps
Switch when you hear the tone.
Frequently asked questions
Yes — set work to 20s, rest to 10s and 8 rounds for classic Tabata, or any custom intervals you like.
Yes — it beeps when work and rest change and counts down the final seconds, so you don't have to watch the screen.
Yes — keep the tab open and your sound on. Everything runs in your browser with nothing to install.
Yes — set work to 20s, rest to 10s and 8 rounds for classic Tabata, or any custom intervals you like.
Yes — it beeps when work and rest change and counts down the final seconds, so you don't have to watch the screen.
Yes — keep the tab open and your sound on. Everything runs in your browser with nothing to install.
Yes — completely free, no sign-up.
Conclusion
Set your work, rest and rounds, press start, and let the beeps run your session while you focus on moving. Keep the tab active with sound on, take the full rest, and it turns any HIIT or circuit into a hands-free workout — free, in your browser.