Interval Timer
Work and rest intervals, rounds and sets, with beeps, voice cues and a big colour display.
Get ready
00:00
Space starts and pauses · ← back · → skip
Click or tap anywhere on this page once so the timer can beep — browsers block sound until you do.
Presets
Saved routines
Sound and display
Every interval in this routine
About the Interval Timer
Set up an interval routine — a warm-up, work and rest intervals repeated for a number of rounds and sets, breaks between sets and a cool-down — or start a preset: Tabata (20 s / 10 s × 8), HIIT 40/20, EMOM, boxing rounds (3 min / 1 min) or a 25/5 focus cycle with a long break after four blocks.
The display fills with a colour for each kind of interval and shows the time left, the round and set, and what comes next, large enough to read from across a room. Beeps count down the last three seconds and mark each change; a voice can call out the intervals using your device’s own speech voices. Every boundary is calculated from the moment the routine started, so the timer does not drift. Share a routine as a link or save it in this browser.
How to use it
- Pick a preset, or enter your own times under Build a routine: warm-up, work, rest, rounds, sets, the break between sets and a cool-down (any of them can be 0).
- Press Start (or the space bar). The display shows the interval, the time left, the round and what comes next; Skip and Back move between intervals, Reset starts over.
- Under Sound and display, set the volume, the countdown beeps, voice cues, notifications and keeping the screen on.
- Press Copy link to share the routine, or Save routine to keep it in this browser.
Examples
10 s get ready, 20 s work and 10 s rest × 8
16 intervals, 4:00 in total (3:50 after the get-ready time)
3 min rounds, 1 min rest × 12, warning 10 s before each round ends
47:10 including a 10 s get-ready
25 min focus, 5 min short break × 4, then a 15 min long break
2:10:00 — focus blocks start at 0:00, 30:00, 1:00:00 and 1:30:00
30 s work, 15 s rest × 5 rounds, 3 sets, 1 min between sets
15 work intervals, 12:30 in total
Common uses
- High-intensity interval training, circuits and Tabata workouts at home or in the gym.
- Boxing, martial arts and skipping rounds with a warning before the bell.
- EMOM training: a new set at the start of every minute.
- Study or work sessions in focused blocks with planned breaks.
The presets
- Tabata: 20 seconds of work and 10 seconds of rest, eight times. In the original study, the subjects did “seven to eight sets of 20-s exercise at an intensity of about 170% of VO2max with a 10-s rest between each bout” on a cycle ergometer, five days a week for six weeks (Tabata I. et al., Med Sci Sports Exerc 28(10):1327-30). With rests only between bouts the eight rounds take 3:50; tick Rest after the last round for the popular 4:00 version.
- HIIT 40/20: 40 seconds of work and 20 seconds of rest, ten times — a common high-intensity format.
- EMOM (every minute on the minute): a beep at the start of each minute for ten minutes; you rest for whatever is left of each minute.
- Boxing rounds: 3-minute rounds with 1-minute breaks and a warning knock 10 seconds before each round ends, for 12 rounds.
- Focus 25/5: four 25-minute blocks of focused work with 5-minute breaks, then a 15-minute break — the rhythm of Francesco Cirillo’s time-management method (Cirillo F., The Pomodoro Technique®). Pomodoro Technique® is a registered trademark of Francesco Cirillo; MySmartCoPilot is not affiliated with or endorsed by him. Make the long break up to 30 minutes if you prefer.
Accurate timing
When you press Start, the timer works out the moment each interval ends — from the start time and the lengths of the intervals, never from the moment the page last woke up — so it cannot drift, even if the browser runs the page late. The beeps are queued a little ahead on the audio clock, which keeps exact time while the page is in a background tab. If the page is paused (for example on a phone with the screen off), it catches up to the right interval as soon as it runs again.
Voice cues
With Voice cues on, the timer says what starts — “Work, round 3 of 8”, “Rest”, “Set 2 of 3”. It uses only speech voices installed on your device, so the words (including interval names you type) are not sent to an online speech service. If your browser has no on-device voice, the option says so and the beeps still work.
Limitations
- The page must stay open. Phones may pause pages in the background or when the screen locks; keep the screen on during a workout (the page asks for this where the browser supports it).
- On iPhone the ring/silent switch can mute website sounds, and voices depend on what the device has installed.
- This is a timer, not training advice. High-intensity intervals are very strenuous — build up gradually and stop if you feel unwell.
Privacy
Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.
Frequently asked questions
What is a Tabata workout?
Eight rounds of 20 seconds of all-out effort with 10 seconds of rest in between, named after the 1996 study by Izumi Tabata and colleagues. The Tabata preset sets it up with a 10-second count-in.
How do I make my own routine?
Change any of the fields under Build a routine — the display and the plan update at once. Rename the intervals under Interval names (for example “Squats” instead of “Work”), then Save routine or Copy link.
Does it keep time in a background tab?
Yes: the timing comes from the clock, not from counting ticks, and the beeps are scheduled ahead. Very long gaps (a phone that pauses the page) are caught up as soon as the page runs again.
Can I use it for studying?
Yes. The Focus 25/5 preset gives four 25-minute blocks with short breaks and a long break, and Show a notification tells you when a block ends if the tab is in the background.
How does the share link work?
The link contains only the routine’s numbers and names. Opening it loads the routine, ready to start. Nothing is uploaded.