Interval Timer: Free Online HIIT and Workout Timer

How to Use This Interval Timer

Set your work time and rest time, pick your rounds and sets, then hit start. A 10-second get-ready countdown gives you time to get into position, and you can adjust it or turn it off entirely.

While it runs, a big clock stays readable across the gym, with a round and set counter and the total time left. Pause, resume, reset or skip a phase in one tap, and beeps mark the last 3 seconds of every phase plus each switch. Turn the sound off if you'd rather train quietly.

Run it full screen, and your screen stays awake the whole time in browsers that support it, so the display never dims mid-round.

Interval Timer Modes: HIIT, Tabata, EMOM, AMRAP, Boxing and Rest

This page opens on interval mode, 40 seconds of work and 20 seconds of rest for 10 rounds, but the tabs switch the whole engine to five other modes: Tabata (20 seconds of work, 10 seconds of rest, 8 rounds), EMOM (a new interval every minute), AMRAP (one countdown for as many rounds or reps as possible), boxing rounds (3-minute rounds, 1-minute rest) and a rest timer with quick picks.

Switch modes any time without losing your setup. Each mode keeps its own defaults and every field stays adjustable, so a HIIT circuit and an EMOM finisher can live in the same tab.

What's a Good Interval Timer Setup for HIIT?

This timer's default, 40 seconds of work and 20 seconds of rest for 10 rounds, is a solid starting point for HIIT: hard enough to raise your heart rate, short enough to sustain across multiple rounds. Shortening the work interval or lengthening the rest makes each round easier to sustain, and the reverse makes it harder.

The name "interval training" covers a wide range of protocols. A landmark study by Tabata and colleagues had subjects on a cycle ergometer repeat 20-second, all-out efforts with only 10 seconds of rest, seven or eight times a session, five days a week for six weeks, and measured a 7 ml/kg/min rise in VO2max plus a 28% rise in anaerobic capacity.

Circuit training works the same way: use your station time as the work interval and your transition time as the rest, with your number of stations as the rounds.

How Do You Save or Share an Interval Timer Setup?

Every setting, work, rest, rounds, sets and prep time, saves into the page's own link. Copy it after you dial in a workout, and it opens with those exact numbers ready to go, so you can bookmark your own routine or send it to a training partner.

Interval Timer Safety Tips

• Warm up before your first hard round, especially when the work interval is short and intense.
• Watch your form as fatigue builds late in a set of rounds, and skip or end a round early if it breaks down.
• Keep water nearby, and lengthen the rest if you need more recovery between rounds.

Frequently Asked Questions

Sources

• Tabata I. et al. (1996), Med Sci Sports Exerc 28(10):1327-30, "Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max"
• Schoenfeld BJ et al. (2016), J Strength Cond Res 30(7):1805-12, "Longer Interset Rest Periods Enhance Muscle Strength and Hypertrophy in Resistance-Trained Men"

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