§ I · Cartography station
The only GPX analyser that isolates a portion of your track

Your GPX track
segment by segment.

Pick a climb, a sprint, a descent — and read elevation gain, pace, gradient and speed for that segment alone. Elsewhere you get the average of your whole outing. Here, you read the part that matters.

Segment analysis Zero server upload No account Free
0server upload0account neededfiles analysed12measures per segment2languages · fr / en

I looked for this reader. I never found it.

I wanted my numbers for one specific portion of my run — the climb of the last two kilometres, not the average of my three-hour outing.

No online analyser lets you isolate an arbitrary portion of a GPX track. They all show the total, or offer Strava segments already drawn by other runners — never my portion, the one that mattered on my outing.

I ended up coding the reader I was looking for. Here it is — open to all, no account, no upload.

Thomas Winkin — Trail runner • Web developer
§ III · Difference

Not the average. The segment.

Same GPX file, read differently.

Other analysers Full outing · 4 h 12
  • Distance 26.21mi
  • Total D+ 4,213ft
  • Average pace 9:10min/mi
  • Average gradient 1.5%
  • Total time 4 h 12
  • Avg V.A.M. 1,003ft/h
  • Avg heart rate 147bpm
  • Max heart rate 184bpm

Same measures as GPXchunk — but aggregated over the four-hour outing. The climb drowns in the flat return leg, the sprint in the warmup. No way to isolate the portion you care about.

GPXchunk Isolated segment · mi 15 → 17
  • Segment distance 2.39mi
  • Segment D+ 1,352ft
  • Segment pace 13:19min/mi
  • Average gradient 10.7%
  • Segment time 31′48″
  • V.A.M. 2,552ft/h
  • Avg heart rate 168bpm
  • Max heart rate 182bpm

Same measures — but recomputed for the segment you pick. Drag two handles on the profile or type the kilometre bounds: the twelve numbers redraw instantly for that segment alone.

§ IV · Readings

What the analyser reveals.

Twelve measures drawn point by point from your GPX file — synchronised between map, elevation profile and selected segment.

01 / segment

Segment isolation

Drag two handles on the profile — or click two points on the map — or type the kilometre bounds. The twelve measures recompute live for the isolated segment. This is the feature no other online GPX reader offers.

Segment analysis
02 / profile

Interactive topographic profile

The terrain of the route, plotted from the altitude of each point. Click anywhere on the curve — the matching marker lights up instantly on the map.

03 / elevation

Filtered real elevation gain (D+)

Computed with a ±1 m GPS noise threshold. No more inflated values from altimeter micro-oscillations. This is the D+ shown by serious sports software.

04 / pace

Pace, speed, V.A.M. & HR

On the selected segment: pace in min/mi, speed in mph, climbing speed in ft/h, average and max heart rate in bpm — from timestamped data. Haversine distance, not linear approximation.

05 / gradient

Smoothed instant gradient

Rolling 50 m average to absorb altitude noise. The gradient you feel, not the one you hallucinate.

06 / map

OpenStreetMap map

Free tiles, overlaid track, two movable markers pinning the segment ends. Zoom, pan, popup — nothing superfluous.

§ V · Procedure

Three steps, nothing more.

01

Drop the .gpx

A .gpx file exported from Garmin, Strava, Komoot, Suunto, Coros, Wahoo, Apple Watch, Polar… It stays in your browser, nothing is uploaded.

02

Isolate the segment

Drag the two profile handles, or click on the map, or type the kilometre bounds: the selection syncs across all three views.

03

Read the measures

Measures update live for the segment alone: distance, time, D+, D−, speed, pace, max altitude, min altitude, net gradient, V.A.M., average HR and max HR.

§ VI · Disciplines

Who this tool is built for.

Any discipline that leaves a GPS track. The readings adapt: a trail runner isolates a climb; a roadie, a final sprint; a hiker, a col crossing.

Trail running Hiking MTB & Gravel Road cycling Ski touring Running Walking & pilgrimage Mountaineering Kayak & rowing Orienteering
§ VII · Privacy & funding

Private processing . Honest funding.

Your GPX file is never sent to a server. XML parsing, haversine distance, filtered elevation gain, Leaflet rendering: it all runs in your browser tab through the FileReader API. Your track never leaves your device — by architecture, not by promise.

The project is free and funded by Google AdSense slots. AdSense sets its own advertising cookies, framed by a consent banner.

You close the tab: your GPX file goes with it — because it never left your browser. Segments you analyse locally.

§ VIII · Questions

What the curious ask.

How is “segment analysis” different?
You pick two points on your track — via the map, via the elevation profile, or by typing mile bounds. The analyser recomputes the twelve measures (distance, time, D+, D−, speed, pace, max altitude, min altitude, net gradient, V.A.M., average HR and max HR) for that segment alone. Other online GPX analysers only show the average of the whole outing — no way to isolate a 1 mi climb inside a 25 mi run.
Which file types are supported?
Any .gpx file compliant with the 1.0 and 1.1 specs. <trkpt>, <ele> and <time> tags are extracted for the track; <wpt> (named waypoints) appear as icons on the map with their name and description. Exports from Garmin Connect, Strava, Komoot, Suunto App, Coros, Wahoo SYSTM and Apple Workout work natively.
Is my file sent to a server?
Never. The entire processing — XML parsing, distance computation, elevation, map and chart rendering — runs in your browser tab. No network request carries the GPX contents. See why this guarantee is architectural, not a promise.
Are there ads?
Yes — Google AdSense slots sit in the page margins to fund hosting and development. They are never embedded in the reader (map, profile, measures, segment). AdSense places its own advertising cookies, controlled by the consent banner on your first visit.
Does the tool work offline?
Yes, once the page has loaded. Only exception: the OpenStreetMap basemap fetches its tiles in real time — the map stays empty without a connection, but the elevation profile and all measures keep working.
How is elevation gain computed?
A 1 m threshold is applied between consecutive points: only variations above it are summed. This dead band filters GPS altimeter noise (typically ±1–2 m even at rest) and gives a realistic D+, close to what Strava or Garmin Connect show. We dig into the calculation in our dedicated guide.
Can I analyse large tracks?
Yes. Tens of thousands of points are processed without slowdown on a modern browser. A 24-hour outing at 1 point/second is no problem.
Is it really free, and unlimited?
Yes. No hidden paid version, no freemium, no file quota. Hosting is covered by AdSense, nothing else.
Is it a GPX analyzer or a GPX analyser?
Both — same tool, two spellings. Analyzer is US English, analyser is British and Commonwealth. The interface here uses the British spelling because that's the author's habit; the search engine maps both to the same intent. Type whichever you'd write naturally — the result is the same page.

Open your next route.

Drop a GPX file, isolate the portion you care about. No sign-up required.

Open the analyser