Free HIIT Timer Online - Custom Work/Rest Intervals with Sounds
Any work/rest ratio, any rounds - sounds, presets, and nothing to install.
How to use this HIIT Timer
Set your work interval, your rest interval, and the number of rounds. Add sets with a break between them if you're running multiple blocks. Hit start: a bell opens work, and 3-2-1 countdown beeps carry you into every switch. Every configuration is a shareable link.
Open a preset on a gym TV's browser and run it full-screen, or keep it full-screen on your phone - the display stays awake through the last round.
What is HIIT - and why the ratio is the whole workout
HIIT (high-intensity interval training) alternates hard work with recovery, and the work-to-rest ratio decides what any HIIT workout is actually training:
- Short work with equal rest (30/30) builds repeatable speed.
- Longer work with short rest (45/15, 60/30) builds conditioning under fatigue.
- Long intervals with long rest (the 4x4 "Norwegian" protocol) push aerobic capacity.
A HIIT timer exists because those switches come every 10-60 seconds and nobody counts them accurately at 90% heart rate - and every ratio below is one tap away in the workout timer hub.
Ratio | Example | Trains | Best for |
|---|---|---|---|
| 1:1 | 30/30, 60/60 | Repeatable power | Beginners, skill-based movements |
| 2:1 | 40/20, 60/30 | Conditioning | Most general HIIT workouts |
| 3:1 | 45/15 | Work capacity under fatigue | Advanced conditioning, class formats |
| 4:1 | 40/10 | Near-Tabata density | Short, brutal finishers |
| 4x4 | 240/180 | VO2max | Runners, rowers, cyclists |
Full ratio-by-goal programming lives in our HIIT intervals chart. For the fixed 20/10 protocol, use the Tabata timer, and for minute-based work, the EMOM timer.
Sounds - and music that follows the intervals
Cue sounds built in: a bell opens each work interval, and countdown beeps carry you into every switch - loud enough for a garage or a full class.
The part no other HIIT timer has: in FitVizPro on iOS and FitViz on Android, FitBeats plays licensed mixes in a dedicated high-output zone that shifts intensity with the intervals - energy pushes on work, drops on rest, no DJ-ing between rounds. Voice cues and pick-your-pack sound options live there too. It's why classes running this free HIIT timer on a gym display sound as sharp as they look.
Why this free HIIT timer
Free, no ads, no signup
Any ratio
Shareable presets
Runs full-screen on any screen
Every format
Frequently Asked Questions
A HIIT timer runs alternating work and rest intervals automatically, with sound cues for each switch, so you train instead of watching a stopwatch. This one adds presets, sets with breaks, and shareable links.
Beginners do best with a 1:1 ratio like 30/30. General conditioning uses 2:1, such as 40/20. Advanced work capacity training uses 3:1, like 45/15. For aerobic capacity, the 4x4 protocol runs 4 minutes on and 3 minutes off. The ratio, not the movement, is the programming decision.
10 to 25 minutes of intervals is the effective range - 10 for beginners, 15 to 20 for most, 25 for advanced 4x4 work. A session that runs much longer usually means the intensity wasn't high enough.
Tabata is one fixed HIIT prescription, 20 seconds on and 10 seconds off for 8 rounds at maximal effort. A HIIT timer takes any ratio. This tool runs both, and the 20/10 preset opens the dedicated Tabata timer.
Sound cues are built in: a bell opens each work interval and countdown beeps carry you into every switch. Voice cues and FitBeats interval-synced music are in FitVizPro on iOS and FitViz on Android.
Open a preset URL in the TV's browser and run it full-screen - the display stays awake through the final round. For actual casting from a phone or tablet, the FitViz Tv app casts directly; for synced multi-screen classes with the workout displayed alongside, that's the Fit Viz workout display.
Completely - no ads, no account, nothing to install. Built by Fit Viz, whose gym platform also starts free.
30 seconds work and 30 seconds rest for 8 to 10 rounds - the 30/30 preset. Add rounds before shortening rest.
Further Reading
CrossFit Software
Tracking + WOD App
Smart Gym Display
Put this on every screen
This timer is free forever. Fit Viz runs it on gym TVs alongside the workout, scheduling, and the rest of the room.