Interval Timer Online
HIIT and workout timer with configurable work/rest rounds. Tabata, circuit training, and more.
Presets
How to Use the Interval Timer
- 1
Configure Your Intervals
Set your work duration in seconds, rest duration, and total rounds. Or pick a preset like Tabata (20s work / 10s rest / 8 rounds).
- 2
Start the Workout
Click Start. The timer begins with a work phase, shown in orange. An audio beep signals each phase change.
- 3
Follow the Phases
Work phases alternate with rest phases. The round counter shows your progress through the total rounds.
- 4
Finish
After all rounds complete, a celebration message appears. Click Reset to run another session.
About Interval Training & HIIT Timers
Interval training alternates between periods of higher-intensity effort and recovery. High-Intensity Interval Training (HIIT) is one of the most scientifically validated approaches to cardiovascular fitness, burning more calories in less time than steady-state cardio and producing an "afterburn" effect that continues for hours after the workout.
The most famous interval protocol is Tabata (20 seconds work / 10 seconds rest / 8 rounds), developed by Japanese scientist Dr. Izumi Tabata in the 1990s. The preset builds are pre-loaded in this timer for instant access. Other popular formats include AMRAP (as many reps as possible in a set work window) and EMOM (every minute on the minute).
This interval timer supports fully customizable work/rest durations from 5 seconds to 5 minutes, and 1–50 rounds, covering everything from sprint training to yoga flow timing. Audio beeps signal each phase transition, keeping you in the zone without needing to watch the screen.
The color-coded display — orange for work, blue for rest — provides instant visual feedback. The progress bar within each phase helps you pace your effort. All processing runs client-side with no data sent to any server.
You may also find our Pomodoro Timer, Stopwatch, and Study Timer helpful.
How to Use
- 1. Set your work interval and rest interval.
- 2. Choose how many rounds to complete.
- 3. Press Start — audio cues mark each switch between work and rest.
Frequently Asked Questions
What is Tabata training? expand_more
Tabata is 20 seconds of maximum effort followed by 10 seconds rest, repeated 8 times (4 minutes total). Use the Tabata preset button.
Can I set rest to 0? expand_more
Yes — set rest to 0 for back-to-back work intervals with no breaks, useful for AMRAP-style circuits.
Does the audio work on mobile? expand_more
Yes, on mobile browsers when the screen is on. Browser autoplay policies require a user interaction first — the Start button counts.
Can I pause mid-round? expand_more
Yes, pause at any time and resume from where you left off.
Is there a warm-up phase? expand_more
Not yet. You can simulate a warm-up by adding a long "rest" round at the start of your session.