Check your GPX before you import it

Inspect the file before importing it

Open the free GPX viewer and file inspector, choose a GPX, and compare the point counts, segments and available dates with the trip you expected. Your file is read in the browser; there is no upload or account.

Choose a destination that explicitly supports GPX; this viewer does not import the file into Whereday. This tutorial uses invented points from a checked Whereday export. It shows what to verify, not proof that a real journey was recorded correctly. Keep your original GPX before converting or editing it.

1. Try the five-point example

1. Open the viewer and choose Try a synthetic example.
2. Expect 5 valid points, 1 track, 2 track segments, 0 routes and 0 waypoints.
3. Check the UTC dates: 2000-01-01 12:00 through 12:14.
4. The two segments contain three points and two points. The 11-minute break between 12:02 and 12:13 is not connected by a line.

Download the exact GPX example and open it with the file picker to check the same result. The demo and download contain the same records.

2. Open your own GPX and check the result

Choose a GPX 1.0 or 1.1 XML file of at most 10 MiB and 50,000 points. On iPhone, save a local copy in Files first if a cloud provider cannot supply it. The tool reads track points, route points and waypoints; these are different GPX objects.

• Point count: Compare valid points with the count in the source app. Points with missing or out-of-range coordinates are counted as omitted.
• Segments: Separate segments can represent pauses or separate recordings. The viewer keeps them separate rather than drawing a trip you did not record.
• Dates: Check UTC dates and times, including the day at either end. UTC can differ from the date displayed in your local timezone.
• Route shape: The local plot has north at the top and no street tiles. It is a shape check, not turn-by-turn navigation. Large files draw a sample of up to 2,000 points; the CSV and GeoJSON downloads include every valid point.

File checks can find structural problems, but they cannot establish whether the GPS followed the road, whether a day is complete, or whether every exported field will be understood by another app.

3. Understand warnings before changing the file

For a deliberately limited example, open the two-point file with a missing timestamp. Expect two valid points and one missing-time warning. A second sample has one out-of-range coordinate: expect one valid point and one omitted point. All sample coordinates are invented.

4. Save a point table as CSV

Choose Download points as CSV. For the five-point demo, expect five data rows plus a header: three rows in group 1 and two in group 2. Latitude/longitude are decimal degrees; elevation is meters; normalized times are UTC. Original timestamp text is retained in its own column.

The table includes only usable-coordinate points. It does not preserve all metadata, extensions or GPX structure and is not a Whereday restore file. User text that could be interpreted as a spreadsheet formula is prefixed with an apostrophe. Keep the original GPX alongside the CSV.

5. Convert GPX to GeoJSON and check the output

1. In the local GPX viewer, choose Try a synthetic example, then Download as GeoJSON.
2. Open the downloaded gpx-points.geojson in a text viewer. Expect a FeatureCollection with two LineString features: three coordinate pairs in group 1 and two in group 2.
3. Check times_utc: group 1 runs 12:00–12:02 UTC; group 2 runs 12:13–12:14 UTC on January 1, 2000. The eleven-minute break stays between features.
4. Check elevations_m: the invented example has values 0, 1, 2 in the first group and 3, 4 in the second. Geometry remains two-dimensional; elevations are custom properties.
5. Before using a personal file in another app, check that app’s support for the property arrays. Seeing the line does not establish that it read times, elevations or names.

Download the exact converted five-point example to compare with the browser’s output. This is the converter’s output from the unchanged synthetic GPX above. The format-choice article’s GeoJSON is a different, hand-controlled comparison representation with a different custom time field; property conventions can vary between files.

A single-point part or independent waypoint becomes a Point feature. An invalid coordinate or a longitude jump over 180 degrees starts a separate part; no boundary coordinates or times are interpolated. Empty parts produce no feature. Coordinate order is longitude, then latitude. Missing or unusable normalized times and elevations remain null; original timestamp text stays in original_times when present. Each custom property array has one value per coordinate, including a single value for a Point.

Point order within each group, duplicates and the viewer’s group numbers are retained. File metadata, track/route names, styling and extensions are omitted; this is not a lossless archive conversion. GeoJSON’s geometry rules and optional height reference are defined in RFC 7946. This tool keeps elevation outside geometry and uses its own documented time/elevation fields. Keep the original GPX.

Before using GPX points for a location heatmap

A location heatmap can help you spot clusters of recorded points. First decide what you want to count: GPS samples, separate visits, or time spent. Those are different questions. This viewer supplies a point table and route plot; it does not calculate a heatmap or visit durations.

1. Start with the CSV. Use the five-point demo above and choose Download points as CSV. In a mapping tool that accepts a coordinate table, select longitude as X and latitude as Y, in WGS84 decimal degrees. Confirm five input rows before applying any density styling. The converted GeoJSON example contains two lines, not a five-feature point layer.
2. Keep the groups and timestamps. In this invented file, group 1 has three samples from 12:00 to 12:02 UTC; group 2 has two from 12:13 to 12:14. The first group supplies three of five samples (60%). That does not mean 60% of the trip was spent there.
3. Leave the gap unknown. The full timestamp span is 14 minutes, but the spans within the two segments total only three minutes. The remaining eleven minutes have no intermediate samples in this file. Do not assign that interval to either endpoint or draw an assumed route through it.
4. Check recording consistency before comparing days. A recorder saving a point every second can contribute many more samples than one saving every minute. Repeated exports can also repeat records. Inspect dates, duplicate warnings and source settings; retain the original and document any filtering in a separate working copy.

For example, QGIS documents a point-density heatmap with a search radius, output pixel size and optional weight field. Those choices change the result: a larger radius smooths over more space. Record the settings and units when comparing maps. The instructions here prepare and check the input; they do not establish a tested QGIS import or a time-weighted analysis.

Before sharing any heatmap or CSV, review whether home, work or repeated routes are visible. Removing names does not remove coordinates. Use the format comparison to check which location fields remain, and use only the synthetic example when testing an unfamiliar service.

If the file will not open

• Wrong format: Renaming JSON, FIT, KML or ZIP to .gpx does not convert it. For a Google archive, use the Google Timeline import walkthrough.
• Malformed XML: Export a fresh GPX from the original recorder rather than discarding the archive. DTD and entity declarations are not supported by this tool.
• Too large: Export a shorter date range in the original app. The viewer caps input at 10 MiB and 50,000 points.
• No points: An outing title or time range is not a GPS track. Check what the recorder actually saved; the missing-history checklist separates recording and export problems.

Keep recording and backup separate

The browser viewer is free and does not require Whereday. To record your own future route, follow the iPhone route and GPX export guide. New-user tracking access and native file-writing access have separate requirements. For a restorable journal copy, use the JSON backup workflow instead of treating a point table as a full backup.

For GPX’s track, route, waypoint and segment definitions, see the GPX 1.1 schema documentation.

Need another format?

Use the GPX, KML, GeoJSON and CSV comparison to check coordinate order, timestamps and grouping before choosing a file for another app. It includes four representations of the same invented trip.