Your files are never uploaded
This tool has no server component. There's nowhere for your files to go — every step of reading, decoding, and combining your fitness data happens inside your own browser, on your own device, using JavaScript running locally (including in a Web Worker, so the page stays responsive on large files). You can verify this yourself: open your browser's developer tools, watch the Network tab, and use the tool — you won't see any request carrying your file data anywhere.
No accounts, no login
There's nothing to sign up for. No email capture, no account creation, no login gate of any kind. You land on the page, pick a file or folder, and get your result.
No cookies, no local storage, no tracking
This site currently sets no cookies and stores nothing in your browser's local storage. It uses no third-party analytics or advertising scripts today. If that changes — for example, adding privacy-focused, cookieless analytics, or ads to help cover hosting costs — this page will be updated first, and any tracking that requires your consent (for example, for visitors in the EU, UK, or Switzerland) will ask for it before it runs, not after.
No API connection to Strava or Garmin
This tool never connects to Strava's or Garmin's servers, and never asks you to authorize account access to either. It only works from files you've already exported yourself and chosen to open in your browser. Nothing is fetched on your behalf, and nothing about your Strava or Garmin account is ever visible to this tool.
What happens to the file you download
Both steps of this tool end in a file downloading directly to your device — there is no cloud copy, no history, and nothing saved anywhere by this tool once you close the tab. Anything you do with the downloaded file afterward — including pasting it into an AI chat — is between you and whatever tool you paste it into; read that tool's own privacy policy for how it handles what you send it.