Parse your .FIT files easily, directly from JS.

Usage no npm install needed!

<script type="module">
  import easyFit from 'https://cdn.skypack.dev/easy-fit';



Parse your .FIT files easily, directly from JS. Written in ES6.


$ npm install easy-fit --save

How to use

See in examples folder:

// Require the module
var EasyFit = require('./../dist/easy-fit.js').default;

// Read a .FIT file
var fs = require('fs');
fs.readFile('./example.fit', function (err, content) {

  // Create a EasyFit instance (options argument is optional)
  var easyFit = new EasyFit({
    force: true,
    speedUnit: 'km/h',
    lengthUnit: 'km',
    temperatureUnit: 'kelvin',
    elapsedRecordField: true,
    mode: 'cascade',
  // Parse your file
  easyFit.parse(content, function (error, data) {
    // Handle result of parse method
    if (error) {
    } else {

API Documentation

new EasyFit(Object options)

Needed to create a new instance. options is optional, and is used to customize the returned object.

Allowed properties :

  • mode: String
    • cascade: Returned object is organized as a tree, eg. each lap contains a records fields, that is an array of its records (default)
    • list: Returned object is organized as lists of sessions, laps, records, etc..., without parent-child relation
    • both: A mix of the two other modes, eg. records are available inside the root field as well as inside each laps
  • lengthUnit: String
    • m: Lengths are in meters (default)
    • km: Lengths are in kilometers
    • mi: Lengths are in miles
  • temperatureUnit: String
    • celsius:Temperatures are in °C (default)
    • kelvin: Temperatures are in °K
    • farhenheit: Temperatures are in °F
  • speedUnit: String
    • m/s: Speeds are in meters per seconds (default)
    • km/h: Speeds are in kilometers per hour
    • mph: Speeds are in miles per hour
  • force: Boolean
    • true: Continues even if they are errors (default for now)
    • false: Stops if an error occurs
  • elapsedRecordField: Boolean
    • true: Includes a elapsed_time field inside each record field, containing the elapsed time in seconds since the first record (default)
    • false

easyFit.parse(Buffer file, Function callback)

callback receives two arguments, the first as a error String, and the second as Object, result of parsing.


Big thanks to Mikael Lofjärd for his early prototype. See CONTRIBUTORS.


MIT license; see LICENSE.

(c) 2016 by Pierre Jacquier