What sameness means
Two files can describe the same outing without containing the same data.
A GPX file is a set of ordered geographic elements, not a fingerprint of a route. Two people can draw the same intended course with different points. Two services can export one source line using different GPX structures. A recorded activity can also follow the same path as a plan while carrying a much noisier trace.
The filenames and map thumbnails may look alike, but the XML can differ in point count, coordinate precision, route direction, segment boundaries, timestamps, elevations, names and extensions. Even a file produced from the same service at two different times may reflect a changed export process or updated terrain data.
Difference alone does not identify an error. The useful question is which differences affect the intended use.
The line itself
Point selection changes shape, distance and how closely a line follows bends.
- Different point densityOne export may keep every recorded sample while another removes points that contribute little to the visible shape. Repeated coordinates are a separate case explained in what duplicate points do in a GPX file.
- Different path choiceA planner may snap to one mapped path while another uses a parallel road, trail centreline or edited alignment.
- Different directionThe same coordinates can appear in reverse order. The picture is similar, but start, finish and progression change.
- Different continuityOne file may preserve several track segments. Another may join them and create a straight connection across the break.
- Different coordinate roundingFewer decimal places slightly move points. Written precision does not guarantee equivalent positional accuracy.
These changes can alter calculated distance even if the lines appear identical at a small map scale. The reasons are explored further in why route distance differs between apps.
More than geometry
The same points can carry different evidence.
One file may include elevation at every point while another leaves it out or replaces it from a terrain model. The second file can then report different ascent despite keeping the horizontal path. Timestamps can be retained, shifted, generated or removed, which changes the durations and speeds that a viewer can derive.
GPX extensions create another layer. A device may add sensor data or application fields that another service ignores on import. Re-exporting the line can leave the standard coordinates intact while dropping those extras.
Names and descriptions matter operationally too. A file with several tracks may label them clearly; a stripped export may leave a user guessing which element to open. File size is therefore a poor measure of route quality. Extra bytes could be detailed geometry, useful timestamps or merely verbose metadata.
A fair comparison
Compare structure first, then statistics.
- Identify
Count routes, tracks and track segments.
Confirm that both files are describing the same object rather than different elements from one collection.
- Orient
Check the first and last coordinates.
This reveals reversal, a shifted start or a trimmed finish before headline figures distract from the geometry.
- Overlay
View the lines together at useful detail.
Look especially at junctions, switchbacks, parallel paths and every discontinuity.
- Audit
Compare point count and optional fields.
Check elevation coverage, timestamp order, names and extensions according to what you need.
- Choose
Prefer the evidence suited to the job.
A clean planned line may be better for navigation. A timed original track may be better for analysing what happened.
Sources & scope
What this answer is based on.
The sources establish GPX's optional structures and one documented simplification method. Export policies vary, so a specific pair of files must be inspected directly.