Free Interval Timer & HIIT Workout Timer

Simple HIIT Timer is a free online interval timer for HIIT, Tabata and circuit training. Set your work time, rest time and number of rounds, then start your workout in seconds, with audio cues, an optional start delay and optional spoken coaching.

No account needed. Sign in to save your workout history and sync it across devices. Works offline as an installable web app.

Quick presets

• 30s on / 30s off: 30s work, 30s rest, 10 rounds
• 40s on / 20s off: 40s work, 20s rest, 8 rounds
• Tabata 20 / 10: 20s work, 10s rest, 8 rounds
• 1 min on / 1 min off: 60s work, 60s rest, 10 rounds
• Running: 1 min fast / 2 min easy: 60s work, 120s rest, 8 rounds
• Sprints: 15s / 45s: 15s work, 45s rest, 10 rounds

How to use the interval timer

Use the plus and minus buttons to set your work time, rest time and rounds, or tap a preset above. Turn on the 5-second start delay if you need time to get into position, and the optional voice coach for spoken encouragement during work intervals. Your settings are remembered for next time, and the timer ends after the last work interval, with no extra rest.

What is interval training?

Interval training alternates short periods of hard effort with periods of rest or easy movement. Because you recover between efforts, you can work harder than you could at a steady pace, which makes intervals one of the most time-efficient ways to build fitness. An interval timer does the counting for you, so every effort and every rest is the same length.

Choosing work and rest times

Think in ratios. A 1:1 ratio such as 30 seconds on and 30 seconds off suits beginners and longer sessions. A 2:1 ratio such as 40/20, or Tabata's 20/10, is harder because you get less recovery. A 1:2 or 1:3 ratio such as 15 seconds of sprinting and 45 seconds of rest lets you go all-out on every effort. Start easier than you think and add rounds before you cut the rest.

Interval timer for running, cycling and rowing

After a 5 to 10 minute warm-up, try 1 minute fast and 2 minutes easy for 8 rounds, or 30 seconds hard and 30 seconds easy for 10 rounds. The same settings work on a bike, rower or treadmill. For a gentler version, alternate 3 minutes of brisk walking with 3 minutes of slow walking using the Japanese walking timer.

Interval timer for HIIT, Tabata and circuits

For bodyweight HIIT, pick 4 to 6 exercises such as squats, push-ups, mountain climbers and lunges, and do one per work interval. For Tabata, use 20 seconds on and 10 seconds off for 8 rounds. For a circuit, treat each work interval as a station and the rest as your time to move to the next one.

Tips for a better interval workout

Turn your volume up or connect a speaker so you hear every switch. Add the timer to your home screen to open it like an app. Warm up before hard intervals and cool down with a few minutes of easy movement afterwards. Sign in for free to save your workout history, build a streak and earn medals.

Interval Timer guides

• The Science Behind HIIT Workouts
• 5 Quick HIIT Workouts You Can Do in Under 15 Minutes
• Heart Rate Zone Training: Optimize HIIT With Your Fitness Tracker

Frequently asked questions

What is an interval timer?

An interval timer counts down alternating work and rest periods for a set number of rounds and signals each switch, so you can train without watching a clock.

Is this interval timer free?

Yes. Simple HIIT Timer is a free online interval timer. It runs in any browser on your phone, tablet or computer, with no download and no sign-up.

Does the interval timer have sound?

Yes. It beeps and says "work" or "rest" out loud every time the interval changes, so you can train without watching the screen. You can also turn on an optional voice coach for encouragement during work intervals.

Is there a HIIT timer app?

You can install Simple HIIT Timer to your home screen from your browser and use it like an app, even offline. There is nothing to download from an app store.

What settings should I use for interval training?

Beginners often start with 30 seconds of work and 30 seconds of rest for 8 to 10 rounds. For more intensity try 40 seconds on and 20 off, or Tabata: 20 seconds on and 10 off for 8 rounds.

Can I use the interval timer for running?

Yes. Set your fast running time as the work interval and your easy jog or walk as the rest, for example 1 minute fast and 2 minutes easy for 8 rounds.

How long can each interval be?

Work and rest can each be set from 1 second up to 999 seconds (about 16 and a half minutes), for up to 50 rounds.

Does the interval timer work with my screen off?

The timer keeps your screen awake during a workout so the countdown and sounds keep going. You can also install it to your home screen as an app.

Can I control the interval timer with my keyboard?

Yes. On a computer, press the space bar to start, pause or resume, and R to stop. The countdown, phase and round also show in the browser tab, so you can follow the workout while another tab is open.

Can I use this as an online interval timer?

Yes. It runs in your browser as a free online interval timer on phone, tablet or computer. Open the page, set your intervals and press START—nothing to install.

Can I use it as an exercise, gym or circuit timer?

Yes. Any workout that alternates work and rest fits: bodyweight exercises, gym sets, boxing rounds or circuit stations. See the exercise, gym and circuit timers below for ready-made presets.

Does it track my workouts?

Yes. Completed workouts are saved to your history, and you earn medals for workout streaks, active days and total training hours. Sign in for free to sync across devices.

More free timers: Workout Timer · Tabata Timer · Gym Timer · Circuit Timer · Exercise Timer · Workout Clock · Japanese Walking Timer · CrossFit Timer · EMOM & AMRAP Timer · Boxing Round Timer · Workout presets · Workout medals