How to Fix Bad GPX Files: Cleaning Noise and Reducing Size
You just finished an epic run or hike. You export the GPX file from your watch, ready to share it or use it for your next adventure. But when you open it, it looks like a mess.
Maybe the line zig-zags wildly even though you ran straight. Maybe the file is so huge it crashes your friend’s older GPS unit.
Bad GPX data is common, but it’s easy to fix if you have the right tools.
Problem 1: The “Jagged” Line (GPS Noise)
GPS drift happens. Tall buildings, dense forests, and deep canyons can bounce satellite signals, making your smooth path look like a scribbled mess.
Why it matters:
- It adds fake distance (zig-zags add up).
- It inflates elevation gain (bouncing up and down).
- It looks unprofessional when shared.
The Fix: You need to “smooth” the data. This involves averaging out the erratic points to find the true path.
👉 Tool: Use the GPX Cleaner to smooth out the noise.
Problem 2: The “Heavy” File (Too Many Points)
Some devices record a GPS point every single second. For a 5-hour hike, that’s 18,000 points.
Why it matters:
- Older GPS units often have a limit (e.g., 500 or 10,000 points).
- Loading the file on a phone can be slow.
- It’s overkill for simple navigation.
The Fix: You need to “simplify” the track. This removes redundant points (like 50 points on a straight road) while keeping the points that define the turns and shape of the route.
👉 Tool: Use the GPX Simplifier to reduce file size without changing the route’s shape.
Which one should I use?
- If the line looks messy: Use the Cleaner.
- If the file is too big: Use the Simplifier.
- If it’s both: Clean it first, then simplify it.
Summary
Don’t let bad data ruin a good route. A few seconds of processing can turn a messy recording into a clean, professional-looking track that works on any device.