About Stamptivity

Stamptivity is a set of free, browser-based tools for cyclists and runners — turning GPX and FIT files into GPS video overlays, stats images, and detailed activity reports. No account, no uploads: everything runs on your device.

Why it exists

Most tools that do this either cost money, require an install, or send your activity data to a server you don't control. Stamptivity is built the other way: the browser is powerful enough to decode GPX/FIT, render video overlays, and crunch zones and splits entirely client-side — so it does, and your files never leave your device.

What's included

• Overlay — live speed, map, and elevation gauges on your ride or run video
• Stamp — shareable stats images from a GPX or FIT file
• Analyze — zones, splits, best efforts, and segment detection
• Compare — two activities side-by-side with synced charts
• Merge and Convert — combine or reformat GPX/FIT files
• Retime — shift GPX/FIT timestamps to sync GPS with video
• Trim — cut a section out of the start, end, or middle of a GPX/FIT file
• Bike Fit — check how a bike fits you, what setup to start from and what to adjust, with optional size and bike comparison

Who's behind it

Stamptivity is built by forgent.id.

Contact

Questions, bug reports, or feature requests — email [email protected], or use the Feedback button in the app footer for something specific to a tool you're using.

For how we handle your data, see the Privacy Policy.