jsonfit is a Javascript library for parsing and converting Garmin FIT files into JSON objects. It current focus is on activity FIT files but other types might be added in the future.
DISCLAIMER This is really early prototype code at this stage! Be advised that things might change and/or brake.
2025-01-19
Please check out https://github.com/wader/fq for a better FIT-parser (and lots of other binary formats)