This is a free, web-based customizable interval timer engineered for High-Intensity Interval Training (HIIT), circuit workouts, and boxing. It features traffic-light color coding (Prepare, Work, Rest) and runs smoothly in any mobile or desktop browser without app installation. Research shows that structured HIIT protocols can improve VO2 max and anaerobic capacity significantly faster than steady-state cardio.
Yes. Once loaded in your browser, it relies entirely on your device's internal clock system. It will continue to track perfectly even if you lose internet connection.
Instant access across all devices without draining storage space, requiring permissions, or displaying aggressive full-screen ads.