Open a .fit file online
Lapline opens the .fit files your watch or bike computer records, right in your browser. You see the whole session (pace, heart rate, laps, route and zones), and the file is read on your device, not uploaded anywhere.
What is a .fit file?
FIT (Flexible and Interoperable Data Transfer) is the file format most sports watches and bike computers use to record a workout: Garmin, COROS, Wahoo, Suunto, Polar, Zwift and many more. It's a compact binary file, so a text editor can't show you anything useful. It holds a reading every second or so (time, position, heart rate, speed, cadence, power, elevation) plus the laps and a summary of the session.
How to open one in Lapline
- Open Lapline and choose Import (the download arrow).
- Drop the .fit file in, or click to choose it. You can pick many files at once.
- The activity opens with its headline numbers, a heart-rate and pace timeline, per-kilometre laps, the route coloured by heart-rate zone, and detailed stats.
Lapline also reads .gpx files. It doesn't read .tcx files yet. Your imports stay in your browser, so next time you open Lapline they're still there, and trends, records and training load build up as you add more.
Why nothing is uploaded
Most online .fit viewers send your file to a server to process it. A .fit file with GPS shows where you run or ride, often starting from your front door. Lapline does all the work in your browser instead: there's no Lapline server and no account, so the file never leaves your device.
Where do I get the file?
Most device apps have an "export original" option. See the step-by-step guides for Garmin, COROS, Wahoo, Suunto, Polar, Zwift, Apple Watch and Strava, or getting a Garmin .fit file in detail.
If a file won't open
Not every .fit file is a workout: watches also write settings, sleep and monitoring files with the same extension, and Lapline will say "no workout data found" for those. A file that was cut off while copying can't be read either; export it again from the device's app.