How to use this Smart Trainer Interval Timer
JustInterval.app is a free, web-based controller for smart bike trainers. Unlike Zwift or TrainerRoad, it requires no installation, no login, and no monthly subscription. It utilizes Web Bluetooth (FTMS) to connect directly to your hardware.
Supported Devices
This ERG mode controller works with most modern smart trainers that support the Bluetooth FTMS protocol, including:
- Tacx: Neo 2T, Flux S, Flux 2 (supports FEC over BLE)
- Wahoo: KICKR, Core, Snap, Move
- Elite: Suito, Direto XR
- Saris: H3, H4
Features
- ERG Mode Control: Automatically sets resistance based on your target watts.
- Visual Cockpit: Large, easy-to-read timer and power numbers for spin classes.
- Workout Creator: Build custom interval sets (HIIT, Sweet Spot, VO2 Max).
- Cloud Save: Share workouts via URL links with your friends or students.