What is an Interval Timer?
An interval timer is a timer optimized for interval training that alternates between exercise and rest periods. It supports various workout protocols including Tabata (20s work/10s rest/8 rounds) and HIIT (High-Intensity Interval Training).
Freely set work time, rest time, and number of rounds, or use built-in Tabata and HIIT presets. No installation needed - use it directly in your browser.
Key Features
Tabata Preset
Loads 20s work / 10s rest / 8 rounds in one click. The timer does not set exercise intensity or choose movements.
Custom Settings
Freely set work time (5-99s), rest time (5-99s), and rounds (1-20) for your workout.
Auto Switching
Automatically cycles work → rest → work with current round and remaining time displayed prominently.
15 Alarm Sounds
Choose from 15 alarm sounds for work/rest transitions. Vibration alerts also supported.
Screen Wake Lock
Requests a screen wake lock while the timer runs in supported browsers. The request may fail or be released during power saving, screen lock, or tab changes.
How to Use
- Step 1: Preset or Custom — Select Tabata (20s/10s/8 rounds) or HIIT preset, or set custom times and rounds.
- Step 2: Configure Alarm — Choose alarm sound for work/rest transitions, set volume and vibration.
- Step 3: Start Workout — Press Start for automatic work → rest → work cycling.
- Step 4: Complete — A completion alarm sounds when all rounds are done. Press Restart to run the same settings again.
Use Cases
Tabata Workouts
Use the 20s work / 10s rest / 8-round timing pattern. The timer does not reproduce the original study workload or guarantee its outcomes.
HIIT Training
Set your own high-intensity interval training program with custom work/rest intervals.
CrossFit & Circuits
Use for CrossFit WODs, circuit training, and various workout programs.
Running & Cardio
Time repeated running and walking intervals. Choose effort and recovery for your own circumstances.
Frequently Asked Questions (FAQ)
What is Tabata training?
The timing format made widely known by Tabata research alternates 20 seconds of work and 10 seconds of rest. This preset runs eight rounds, totaling four minutes. The original study tested a specific high-intensity cycling program with a small trained group; the timing alone does not guarantee the same outcomes.
What's the difference between HIIT and Tabata?
Tabata is a specific type of HIIT. HIIT is the general term for high-intensity interval training with flexible work/rest times and rounds. Tabata is a fixed protocol of 20s work / 10s rest / 8 rounds.
Can I customize work/rest times and rounds?
Yes, freely set work time (5-99s), rest time (5-99s), and rounds (1-20). Tabata and basic HIIT presets are also available.
Can I pause during an interval?
Yes, press the pause button at any time during work or rest. Resume to continue from where you stopped.
How can I use the interval timer beyond workouts?
Study sessions (focus/rest cycles), cooking (timing each step), presentation practice, and more. Freely adjust work/rest times and rounds to fit any scenario.
Can I see the current and remaining rounds during interval?
Yes, the screen shows current/total rounds, remaining time, and work/rest status in real time.
The Science of HIIT: Why Intervals Work
EPOC (excess post-exercise oxygen consumption) can keep oxygen use above baseline during recovery after hard exercise. Its duration and added energy expenditure vary widely, so it should not be described as a fixed percentage or as guaranteed fat burning for a set number of days.
Repeated training may produce cardiovascular and muscular adaptations, but a short interval session cannot be assumed equivalent to a much longer continuous workout for every outcome or person. The four minutes in a Tabata timer cover only the work/rest blocks; warm-up, cool-down, and recovery still take additional time.
HIIT can be strenuous. Seek individualized guidance from a qualified health or exercise professional if illness, pregnancy, injury, or symptoms during exercise are a concern.
Popular Interval Protocols Compared
Tabata (20s work / 10s rest / 8 rounds): The 'about 170% of VO2max' language in the 1996 cycling study referred to workload relative to the power associated with VO2max on a cycle ergometer. It did not mean 170% of maximum heart rate. A small group of trained participants followed the protocol for six weeks, so the result should not be generalized to every exercise or person; this timer supplies only the timing pattern.
EMOM: Start a chosen amount of work each minute and recover for the remainder. Set the movement and repetitions in advance without making the recovery disappear.
AMRAP: Record safe, technically sound rounds within a set window. Keep the movements, range, and conditions consistent if comparing sessions.
60s/75s intervals: Some research and training formats alternate a 60-second effort with 75 seconds of recovery. It is not automatically suitable for beginners; reduce effort or rounds to match the person and stop for pain, dizziness, or unusual symptoms.
Interval Protocol Comparison: Workout, Study, and Daily Routines
The same repeating work/rest timer can mark intervals for workouts, study, and daily routines. These eight rows are timing examples you can enter in the current tool, not a list of proven exercise prescriptions or learning outcomes. Total time includes the final round of rest.
| Protocol | Work | Rest | Rounds | Total Time | Use case |
|---|---|---|---|---|---|
| Tabata preset | 20s | 10s | 8 | 4 min | 20/10 timing cue |
| HIIT preset | 40s | 20s | 6 | 6 min | 40/20 timing cue |
| One-minute blocks | 55s | 5s | 10 | 10 min | Cue at each minute |
| Movement practice | 30s | 30s | 10 | 10 min | Mark work and rest |
| English Shadowing | 60s | 30s | 10 | 15 min | Mark practice and review |
| Quiet interval | 45s | 15s | 10 | 10 min | Mark focus and pause |
| Language Self-Intro | 30s | 30s | 6 | 6 min | Mark speaking and review |
| Vocabulary Drill | 60s | 15s | 20 | 25 min | Mark recall and review |
The Tabata preset loads 20s/10s/8 rounds and the HIIT preset loads 40s/20s/6 rounds. Enter the other examples with Custom. Work and rest each support 5–99 seconds and rounds support 1–20. This tool signals the intervals; it cannot assess exercise intensity, technique, or learning results.
Privacy Notice
On this device, browser storage may keep interval work/rest seconds, round count and progress alongside sound, volume, vibration, timer and Pomodoro settings. The tool does not ask for movements, repetitions, weight or heart rate. Settings are not synced across devices and cannot be restored if site storage is blocked or cleared. If you accept analytics cookies, timer start/completion events may send the mode and configured time values to Google Analytics. See the Privacy Policy and Cookie Settings for details; delete clock-tani.com site data to clear local settings.