A track file
is not terrain.

What this inspects

GPX 1.1 only, using the standard default namespace http://www.topografix.com/GPX/1/1 and unprefixed GPX element names. Tracks, segments, routes and waypoints are inventoried separately. Inventory order is tracks, then routes, then waypoints, preserving source order within each type. Converter singleton Points may precede their multi-point track feature. It refuses malformed XML, DTD/entity declarations, unsupported nesting, duplicate elevation/time fields, invalid numeric coordinates and unsupported files. This is not full GPX schema validation. All metadata is a file claim, not a verified author, location or timestamp.

Input is UTF-8, up to 2 MiB, 80,000 XML elements, 2,000 groups and 10,000 points. XML encoding declarations must be UTF-8. Latitude accepts -90 through 90; longitude -180 through less than 180. Elevation accepts finite metres from -20,000 to 100,000 as a practical input bound, not a GPX schema rule. All vendor extensions and foreign-namespace elements are removed before conversion and counted as ignored elements. No sensor readings are reported. Missing elevation remains missing, not zero. Elevation zero is retained.

Gaps, times and singleton points

Track segments are independent continuous spans. We never add a line between segments or groups. The base converter already preserves multi-segment geometry. Our adaptation keeps missing point times as null in their coordinate-array positions, including completely untimed segments, and keeps a single-point track/route group as a Point feature. Empty groups remain in the inventory with no geometry. Route point times are aligned too. This report is not a byte-preserving or lossless GPX round-trip.

Times are preserved as strings. Missing means no time element; blank or malformed/unsupported time strings count as invalid. The supported check is a real calendar date, year 1000–9999, seconds 00–59, optional fractional seconds and an explicit Z or numeric offset. Leap-second 60 and floating local times are unsupported, not silently changed. No elapsed-time, speed, distance, ascent, duration or fitness estimate is computed. Valid-looking times can still be false or out of order.

The diagram is not a map

The diagram uses a minimal covering longitude arc, found by leaving out the largest empty longitude gap, and plain latitude/longitude degree coordinates. A small dateline crossing therefore does not automatically span the whole plot. This is not a geographic projection, equal-distance/equal-area chart, basemap or navigation aid. Shapes near poles and widely distributed tracks can be misleading. Segments spanning the chosen longitude cut can wrap across the diagram. It has no terrain, roads, hazards, borders, routing or scale.

JSON contains counts, a full point-indexed group inventory, the covering extent and adapted converter geometry. Multi-point segments remain LineString/MultiLineString; singletons become Point. Geometry preserves source longitude order and is not guaranteed to be antimeridian-cut RFC 7946 GeoJSON. The converter may retain names, descriptions, links and other basic metadata as data. It ignores file-level metadata and may derive track properties from descendant point metadata. Use the inventory, not inherited feature-level time, for point/time alignment. No metadata is executed or fetched.

Privacy and sharing

File parsing, conversion and drawing run in this page, with no map tiles, remote route lookup, analytics, uploads, cookies or persistent track storage. The synthetic example is a same-origin static file. Tested app flows request only their own code and that example. Hosting logs, browser extensions, OS history and downloaded files are outside these claims. Reports contain precise location/time data and may retain names, descriptions and links: they are not sanitized, private to a recipient or anonymous. Review before sharing. Clearing hides the current report and discards the app's reference; it is not a secure-memory erase guarantee.

Open source

GPX conversion adapted from Mapbox togeojson, revision 126abe9ed9104a23fcff0416d42a4363c85643a6, version 0.16.2, BSD 2-Clause. Full original copyright, terms and disclaimer. Changes: GPX-only module, remove KML/XML serialization and sensor-array accumulation, align missing times with nulls, preserve singleton track/route groups as Points. New strict preflight, inventory, extent, diagram and UI use project-only MIT terms in LICENSE. Notices. No other runtime libraries or third-party fonts.

GPX 1.1 schema documentation defines segment continuity. Another converter's documentation also describes conversion/time-alignment limits. We do not claim category novelty or certify third-party tools. Download source and licence texts · Chawso Credits. Revised November 13, 2026.