TIME TOOLS
Free Online Interval Timer
Create a workout timer with alternating work and rest periods. Set your intervals and rounds, then stay on track with clear visual and sound cues.
Your interval timer
Choose a workout preset or build your own intervals.
Time remaining in work interval
Ready to start
No installation needed. Your session runs locally in this browser tab.
Train with repeating work and rest intervals
Use this free online interval timer for HIIT, Tabata-inspired sessions, stretching, practice drills or any routine where you alternate activity and recovery. Enter work duration, rest duration and rounds. The timer moves to the next interval automatically and ends after the final work period.
Clear phase changes and sound cues
The display shows the current phase, round number, time left in the interval, next phase and remaining session time. Choose one of five synthesized alarm sounds, adjust volume and optionally hear short warning beeps during the last three seconds of each interval.
Frequently asked questions
What is the difference between work and rest?
Work is the active period. Rest is the recovery period between rounds. The session ends immediately after the final work period, without adding one more rest interval.
Can I set rest time to zero?
Yes. Set both rest inputs to 0 to run work intervals consecutively; a new round still begins at each work interval boundary.
Does the interval timer work in a background tab?
While the tab remains open, the current interval is calculated from elapsed time rather than accumulating timer callbacks. Browsers can throttle background JavaScript, so audible cues may be delayed or missed.
Does it work on phones?
Yes, the layout adapts to phones and tablets. Browsers may suspend sound and JavaScript when a device is locked; do not rely on this website for safety-critical timing.
Are there any downloads or accounts required?
No. The interval timer runs in your browser without registering or installing anything. Settings and the session are not uploaded to a server.
Explore more timer tools
Need one countdown, a stopwatch or a focus routine? Try another free WebToolGarden timer.