How to use Interval Timer

Interval Timer is a free web app for boxing, kickboxing, MMA and other combat sports, and for HIIT and Tabata training. No install or sign-up—open it in your browser and start. The remaining time fills your phone, tablet or PC screen, so you can read it from across the room.

Get started

1. Open the timer with an internet connection. Defaults are 3-minute rounds, 1-minute rests and unlimited rounds.
2. Check device volume and try sounds in Settings → Audio & alerts if needed.
3. Press Start. A 5-second preparation countdown plays before the first round.
4. Rounds and rests switch automatically. Pause stops the clock; Resume continues from the same point.

Reading the display

READY means the initial preparation countdown. ROUND 1 shows the active round number, and REST 1 is the rest after round 1. FINISH appears after your chosen number of rounds. There is no rest after the final round.

The large digits show remaining time. Rest digits and the phase label turn yellow. The progress bar turns red during the last 10 seconds of rounds and rests, or from the start for intervals of 10 seconds or less. It fills from left to right as time passes.

Desktop, phone and tablet screens

• Landscape screens: Minutes and seconds appear on one row, such as 03:00.
• Portrait screens: By default, minutes appear above seconds. Choose one row in Settings → Time → Digits on portrait screens.
• Tall desktop windows: The same one-row/two-row preference applies whenever the window is taller than it is wide. Rotating the screen or resizing the window updates the layout.

Press the fullscreen button (right of the Settings button) or the F key to hide the browser tabs and bars. Press it again or Esc to return. On Android, it appears only in landscape. iPhone browsers do not support fullscreen.

Settings and buttons

Open Settings with the gear button at the top left.

Pause and reset remain visible while timing, so you can stop the clock quickly. Tapping the timer display alone does not pause it.

Ads appear only where they do not get in the way of the digits and buttons. If there is no room, no ad is shown.

Set up your training

Change round, rest and repeat settings in Settings → Time. Enter 3:00 for three minutes or 30 for thirty seconds, or use the quick choices and adjustment buttons. Rounds can be 1 second–60 minutes, rests 0–60 minutes. A zero-second rest goes straight into the next round.

Choose a repeat limit to set a finite number of rounds. Preparation and resume countdowns can each be 0–60 seconds; zero skips the countdown. Resume defaults to zero. Apply settings to save; closing the panel alone does not save changes.

Change settings during training

Settings remain available while running or paused. Changes to time, repeats, alerts and volume are normally saved with Queue for next round. They leave the current round and its following rest unchanged. Changes made during rest apply from the round after that rest.

Changes made during the preparation countdown apply from round 1. If there is no next round (for example, in the final round), they apply from the next start. When you save, the app tells you when changes take effect. Digit layout applies immediately.

Choosing sounds

In Settings → Audio & alerts, choose the volume and the start/end sound for rounds (gong or beep). Also check your device volume.

The start/end sound and the beeps for the preparation and resume countdowns always play.

For in-round alerts, choose voice or beeps (beeps by default) and turn each alert on or off. The voice speaks the same language as the screen. Under each alert, you can see the clock time when it will play with your current settings.

• Final countdown: On or off separately for rounds and rests (on by default). With voice, it reads out 10 seconds left and 3, 2, 1. With beeps, it plays a triple beep at 10 seconds and single beeps at 3, 2, 1.
• Time check: Repeats at your chosen interval from the start of the round. The beep pattern is long–short.
• Halfway: Plays once at the halfway point of the round. The beep pattern is long–long.
• Almost done: Plays once at your chosen time left. The beep pattern is long–short–short.

Time check, halfway and almost done play only during rounds, not during rests.

Example: two alerts, mid-round and near the end

For a 3-minute round, set time check every 120 seconds and almost done at 30 seconds left: alerts play when the screen shows 1:00 and 0:30. With time check every 60 seconds, it plays twice (2:00 and 1:00), so the count depends on the interval.

When the final countdown is on, other alerts in the last 10 seconds do not play. If alerts fall at the same moment, only one plays, in this order: start/end sound, countdown, almost done, halfway, time check.

Listen to the preview

Settings → Preview lists the sounds for preparation, one round and its following rest, using your draft settings. The left-hand times are the remaining time at each sound. Row spacing does not represent real duration.

Preparation happens only once at the start; the rounds and rests inside the dotted frame repeat.

Presets and saved settings

In Settings → Presets, name and save your time, repeat and sound settings to load later. Boxing, HIIT, Tabata and other presets are included. Loading does not start the timer. The top preset (Default) is used every time you open the page; to make another preset the default, choose “Move to top (make default)” from its ••• menu. Starred presets (up to 4) appear at the top left of the timer screen—click them or press 1–4 to load (hidden while the timer runs). You can also rename, overwrite and delete presets.

Settings and presets are saved in this browser. They do not sync to other devices and are deleted if you clear browser data. Digit layout is saved separately from presets.

Reloading restores saved settings before the start; it does not restore a session’s remaining time or round number. Tabs run independently and do not stop one another automatically.

Offline use

The timer is meant to be used online. Timing continues if the connection drops after opening. Supporters can store screens and sounds on the device to launch offline. If the browser clears that storage, connect once and reopen the page.

Keyboard shortcuts

Keyboard shortcuts do not work while typing. While Settings is open, only the arrow keys and Esc work.

Need help? Check the troubleshooting steps on the contact page.