FIT Activity Triage
A local triage desk for damaged or awkward FIT activity files. Read the real binary message stream, preserve complete native and developer bytes, and separate checksum repair from missing-data recovery.
How we build a check
This workbench processes supported inputs locally. We test calculations, file structure and generated artifacts using independent readers or known fixtures where available. The example runs the same processing path as a supplied input; it does not stand in for checking your own result.
Editorial responsibility
KitForma maintains this tool and its guides. The source notes on the tool page link to the supporting documentation. We do not claim affiliation with the referenced hardware manufacturers or platforms. Review date: 2026-10-19.
Limits and updates
FIT protocol 1/2 with a complete 12/14-byte header; 16 MiB, 100,000 record messages and a 30-second worker limit. Sequential prefix salvage only, no resynchronization or encrypted/raw-memory repair. CSV projects documented standard sensor fields; GPX keeps valid timed coordinates and elevation only. No developer-field decoding, summary regeneration or guaranteed platform import. If a specification changes or a result appears incorrect, send the relevant source URL and a non-sensitive reproduction to kitforma@outlook.com.
Open-source components
The tools use self-hosted open-source components appropriate to each format, including PDF.js, pdf-lib, fflate, SheetJS, MediaInfo by MediaArea.net SARL and others. Component versions and licenses. MediaInfo license · fflate license.