HIIT Timer

HI

Ready when you are

Set work, rest, and rounds, then start — the config panel collapses so the timer fills the screen.

More fitness timers

Tabata Timer

HIIT Timer

High-intensity interval training timer with customizable work, rest, and rounds. Free online HIIT timer. Open this page, click Start, and follow the on-screen phase cues. Sound alerts mark each transition — no app install required.

High-intensity interval training (HIIT) burns calories efficiently by alternating intense work periods with short recovery breaks. Customize work time, rest time, and rounds to match your workout plan.

Customize sounds and durations from Settings (when available). Share this page or bookmark it for your next session.

Frequently asked questions

How do I use the HIIT Timer timer?
This page is pre-configured for HIIT Timer. Click Start to begin. Work and rest phases alternate automatically with sound cues at each transition.
Will the timer work if I switch tabs?
The timer runs in your browser while this tab stays open. Switching away may delay updates on some devices — keep the tab active for reliable timing.
Can I change work and rest durations?
Yes. Use the configuration panel to adjust work time, rest time, rounds, and audio preferences before starting.

How To Use

A high-intensity interval timer with customizable work, rest, and rounds. Use the settings panel to set your work / rest durations and round count, then start — the config panel collapses so the timer fills the screen.

  1. Open the settings panel and choose work (5–120s), rest (5–120s), and rounds (1–20). The 5-second warm-up before round 1 is optional.
  2. Press Start workout. The session begins in the warm-up phase if you turned it on, then alternates Work and Rest automatically.
  3. Press Pause to freeze the timer, or Skip to jump to the next phase. Press Escape (or hold the Stop button on Tabata) to end early.
  4. Toggle the Motivator for spoken encouragement, Background music, and pick a male or female Coach voice.
  5. When the session ends, choose New session to reset or open Settings again to change durations.

Keyboard shortcuts

SpacePause / Resume
EscStop immediately
SSkip the current phase

Keyboard shortcuts are disabled when focus is in an input field.

Tips

  • The Motivator, Background music, and Coach voice settings save in your browser and apply on your next session.
  • If the timer is running, supported browsers keep the screen awake automatically so the display does not dim mid-workout.
  • Use the fullscreen icon for a larger display during training.
  • Timing preferences are saved in your browser. Refreshing or leaving the page during a session resets progress.