Interval Timer
HIIT, Tabata and circuit training. Set work, rest, and rounds — audio beeps on every phase change.
Work duration
20s
Rest duration
10s
Rounds
8
Prep countdown
5s
About the Interval Timer
Interval training alternates periods of high effort with recovery to build fitness more efficiently than steady-state exercise. This timer handles any work/rest combination with a visual phase display and audio cues.
Built-in presets
- Tabata — 20s work / 10s rest × 8 rounds. The classic protocol.
- HIIT 30/15 — 30s work / 15s rest × 6 rounds.
- HIIT 45/15 — 45s work / 15s rest × 4 rounds.
- Boxing — 60s work / 30s rest × 5 rounds.
Or set your own durations: work from 5s to any length, rest from 5s upward, up to any number of rounds.
Frequently Asked Questions
What is Tabata?
Tabata is 20 seconds of work followed by 10 seconds of rest, repeated 8 rounds. It was developed by Dr. Izumi Tabata and is proven to improve both aerobic and anaerobic fitness in just 4 minutes.
What is HIIT?
HIIT (High-Intensity Interval Training) alternates short bursts of intense exercise with recovery periods. Common ratios are 30:15, 45:15, or 1:1. This timer supports any work/rest combination.
Does the timer make sounds?
Yes. Beeps play at each phase change and count down the final 3 seconds of each phase using the Web Audio API — no external audio files needed.
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