Garmin Connect has no lap editor – here's what to do instead

If you came here trying to edit laps in Garmin Connect, here's the short answer: you can't. Garmin Connect lap editing isn't a feature. You can open an activity and read the lap table, but there's no way to move a lap boundary, split a lap, or merge two of them. The numbers are fixed the moment the file is saved.

That's fine until the laps are wrong. Below is what actually went sideways, and a way to fix it that takes a couple of minutes in your browser.

What goes wrong with laps

A few things, all common:

• Accidental press mid-effort. You bump the lap button during a hard rep and a single interval becomes two ragged halves.
• Late or early press at an interval. You hit lap a few seconds after the turn, so the rest interval eats the start of the next rep – every split after it is skewed.
• Autolap at the wrong distance. Your watch is set to autolap every 1 km, but you wanted splits by climb, by race section, or by 5 km block. The data is all there; the boundaries just land in the wrong places.

None of these touch your GPS track, heart rate, or power. The recording is good. Only the lap markers are off – and those are exactly the thing Garmin Connect won't let you change.

The fix

The activity file itself – the .fit – holds everything your watch recorded, second by second. Lap boundaries are just markers inside it. If you can edit those markers without disturbing anything else, the laps are fixed. That's what ButterLaps does.

Three steps:

1. Export the original .fit from Garmin Connect. On the Garmin Connect website in a desktop browser – the phone app can't do this – go to Activities → All Activities, open the activity, then click the gear icon in the top-right corner. Choose Export File: that gives you the activity in its original device format, which for most watches is the complete .fit your watch recorded. Skip Export to GPX and TCX – those are re-encoded copies, and ButterLaps edits the original .fit.
2. Edit the laps in ButterLaps. Open the file in your browser. The activity is plotted on an interactive chart with your pace, heart rate, power, cadence, and elevation. Lap boundaries are draggable markers: drag one to move it, double-click to add a split, or drop a marker onto its neighbour to merge two laps. The lap table updates live as you go.
3. Download the corrected file. Before you export, a summary shows exactly which boundaries changed. Download the new .fit and you're done.

It all runs in your browser. Your file is parsed, edited, and exported locally – nothing is uploaded to a server, there's no account, and there's nothing to install. The export rewrites only the lap records: your GPS track, sensor data, device metadata, and any unknown or vendor-specific messages survive unchanged. Lap summaries are recomputed from the data you actually recorded, including Stryd developer fields.

An honest note about re-importing

This is the part most tools skip, so here it is plainly. Garmin Connect doesn't let you replace an activity with a corrected file. If you upload the fixed .fit, it shows up as a separate, manually imported activity – not an update to the original. Strava has no replace either: your only option there is to delete the activity and re-upload, which loses the kudos, comments, and segment efforts attached to it.

One more Garmin-specific thing to know: after you upload the edited file, Garmin Connect may still show the original Intervals view rather than your corrected laps. This is because modern Garmin watches write a second, independent layer of interval data into the file based on gait analysis – and ButterLaps preserves that layer untouched, as it should. To get Garmin Connect to rebuild its interval groupings around your new laps, open the activity, go to Edit → Edit Intervals, change at least one lap's Step Type and save – you can change it back in a second save if you want, but Garmin Connect needs at least one real change before it will let you save at all. Garmin Connect will then re-derive the interval breakdown from the current lap sequence. If you don't want any interval grouping at all, assign a different Step Type to each lap; if you want all laps treated as one block, give them all the same type.

So if your goal is a clean replacement on the platform, there isn't a perfect path on either service. That's a limitation of Garmin Connect and Strava, not something ButterLaps can paper over.

It's worth knowing this is mostly a Garmin-and-Strava problem. Training logs built around analysis rather than a social feed – Runalyze is one, and there are others in the same vein – generally don't tie kudos and comments to an activity, so re-importing a corrected file tends to cost you little. If you do your real reviewing there rather than on Strava, the whole re-upload worry largely goes away.

Here's the turn, though: ButterLaps is useful even if you never re-upload. Most of the value is in looking at the run, not re-filing it. Reslice a marathon into 5 km blocks and see how each one held up. Separate a long climb from the descent that followed. Take an interval session where the laps drifted off the reps and reframe it so the splits finally line up with what you actually ran. None of that requires saving anything anywhere – you load the file, see it the way you meant to, and move on. Export only when you want the corrected file in hand.

Recorded on an iPhone or Apple Watch?

If your activity came from an iPhone or Apple Watch rather than a Garmin, you just need a way to get a .fit out first. Three options, all of which drop straight into ButterLaps:

• Native Apple Workout app, via HealthFit. Workouts recorded with Apple's built-in app live in Apple Health. HealthFit – a third-party app, and a genuinely excellent one – reads Apple Health and exports a .fit file. If you record with the stock app, this is the path.
• WorkOutDoors. A superb app, and a favourite among data-minded runners and cyclists for its endlessly configurable maps and screens. It records the workout itself on your Apple Watch, in place of the native app, and exports .fit directly.
• Stryd's app. If you run with a Stryd pod – a great bit of kit for anyone serious about running power – its app records the run and exports a .fit directly.

(If you record on a Garmin watch with a Stryd pod, there's nothing special to do – the Garmin saves the activity and Stryd's numbers are embedded in the Garmin .fit as developer fields. Just follow the export-from-Garmin-Connect path above.)

ButterLaps supports running, cycling, walking, and hiking. It doesn't handle multisport or swimming.