NeverChill

Free tool

Rewrite the manufacturer and device on a FIT file.

Rewrite the manufacturer, product, and serial number on a Garmin FIT file. Anonymize activities before sharing, fix third-party apps that wrote the wrong device tag, or unify rides from multiple head units under a single device name on Garmin Connect. Supports Garmin Edge, Fenix, Forerunner, Wahoo ELEMNT, Coros, Polar, Suunto, and any custom manufacturer enum. Free, in-browser, no upload.

0F A3 21 B7becomesGarmin Edge 840

How it works

  1. 1

    Drop a FIT file

    Original recording from any watch or head unit.

  2. 2

    Pick the new device

    Manufacturer dropdown plus a product and serial number - free text, your call.

  3. 3

    Download the rewritten file

    file_id and device_info messages are updated so platforms display the device you want.

What you get

  • Updates manufacturer, product, and serial in file_id and device_info messages
  • Garmin, Wahoo, Suunto, Polar, Coros, Stages, Bryton in the dropdown
  • Free-text product field for exotic or vendor-specific enums
  • Serial number override or randomisation for anonymization
  • Re-encoded via the official Garmin FIT SDK for round-trip safety
  • Works offline - file stays on your device, no signup required

When to use this

Reach for the device changer when the recorded device on a FIT does not match reality, or when you want to anonymize a file before sharing. Common scenarios: a third-party recording app (RWGPS, Wahoo Fitness on iPhone, some Connect IQ data fields) wrote a generic "Garmin Connect Mobile" or wrong manufacturer tag and you want the file to show your real head unit; a Garmin Edge died mid-recording and you transferred the file but Garmin Connect refuses to attach it to your account because the serial does not match; you want to share a public route file from your forum account without exposing your specific device fingerprint. Each case has the same fix - rewrite the manufacturer, product, and serial to whatever you want.

How it works under the hood

The tool decodes your FIT using the official Garmin JavaScript SDK in your browser. It finds the file_id message (always the first record in a valid FIT) and rewrites the manufacturer, product, and serial_number fields. It then walks the device_info messages, finds the entry whose serial matches the original file_id serial (this is the recording device, as opposed to paired sensors), and rewrites the same three fields there. Paired sensor device_info entries are left alone so HRM and power-meter metadata stays correct. The file is then re-encoded through the SDK's encoder with correct CRC and headers, producing a fully valid FIT that Strava and Garmin Connect will accept on re-upload.

Common mistakes

Three to flag. First, picking a manufacturer and product combination that does not actually exist - Strava and Garmin Connect both check the manufacturer/product pair against known devices and may show "Unknown" if the combination is invalid. Use real manufacturer-product pairs from the dropdown. Second, expecting Garmin Connect to re-link the activity to your account based on a generic manufacturer tag - Connect uses the serial number as the primary key, so you need the exact serial of the paired device on your account for clean re-attribution. Third, anonymizing a file for public sharing without also stripping privacy zones around home - the device change hides your hardware fingerprint but not your address. Run the file through our [GPX Privacy Stripper](/tools/gpx-privacy-stripper) too.

Frequently asked questions

Why would I change the device on a FIT file?
Three common reasons. First, a third-party recording app (RideWithGPS app, Wahoo Fitness, some Garmin Connect IQ data fields) wrote a generic or wrong device tag and you want the file to show your real head unit. Second, anonymizing before sharing - the serial number can identify a specific device, which carries privacy implications when sharing publicly. Third, unifying activities across multiple head units (you ride a Wahoo on the road and a Garmin off-road but want everything to appear as one device on Strava).
Will Garmin Connect re-attribute the activity to a different paired device?
It tries. Garmin Connect uses the file_id manufacturer + product + serial combination to identify which paired device an upload came from. If those three fields match a device on your account, the activity lands under that device. If they do not match (because you wrote a different serial), the activity lands as "Other Garmin device" or under a generic bucket. For clean re-attribution, set the serial to match the actual paired unit.
How do I anonymize a FIT file before sharing publicly?
Use the device changer with the "Randomise serial" option enabled, which writes a random serial number that does not link to your actual device. Combine with our [GPX Privacy Stripper](/tools/gpx-privacy-stripper) to also trim the start and end of the activity (removing your home address) and scrub athlete-name metadata, and you have a fully anonymized file safe to share on a forum or route-aggregator site.
What manufacturers and devices are supported?
The dropdown includes all major manufacturers: Garmin (Edge 530/540/830/840/1030/1040/1050, Fenix 6/7/8, Forerunner 245/255/265/955/965, etc), Wahoo (ELEMNT BOLT/ROAM/RIVAL), Coros (Pace/Apex/Vertix), Polar (Vantage/Grit/Ignite), Suunto (Race/Vertical), Stages, Bryton, Lezyne. For exotic devices or vendor-specific enums not in the dropdown, use the free-text product field with the Garmin product ID.
Will Strava show the new device after the change?
Strava reads the manufacturer and product from the file_id message and displays them on the activity page. Re-upload the rewritten file (after deleting the original or shifting the start time with our [FIT Time Adjuster](/tools/fit-time-adjuster) to avoid duplicate detection) and the new device shows up. Strava does not validate that the device is one you actually own - if you write "Edge 1040" the activity will display as recorded on an Edge 1040.
Does this change any of the recorded data?
No - only the manufacturer, product, and serial fields in the file_id and device_info messages are rewritten. The record stream (lat, lon, elevation, HR, power, cadence, speed, temperature, distance), laps, sessions, and event messages are untouched. Activity stats, route, and stream data are identical before and after the device change.
What if my activity has multiple device_info messages (paired sensors)?
FIT files often have multiple device_info messages - one for the head unit and one each for paired sensors (HRM, power meter, cadence sensor). The tool only rewrites the device_info entry that matches the file_id (the recording device itself); paired sensor entries are left alone. This means HR-strap and power-meter metadata stays accurate while the head-unit identity changes.
Is the device changer free?
Yes - free, no signup, no upload. The tool exists because changing the recorded device after the fact is something Garmin Connect, Strava, and every other platform refuses to let you do, even when the recorded device is wrong.

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