Geo Conversion Loss Inspector
Converts a geo file to another format and tells you exactly what changed, rather than stopping at "conversion complete." GPX has no polygon concept, KML keeps only a name and description per feature, WKT keeps no properties at all, and CSV holds one point per row — every real converter hits these limits, but few show you exactly what got left out. This tool runs the real conversion using the same lib/geo/serializers logic as the Geo Format Converter, reads the output back in through the same parser a real import would use, and directly diffs it against the source: which geometry types disappeared, which property keys didn't survive, how the feature count changed. Findings are grouped the same way as the YOLO/COCO/Pascal VOC Dataset Health Checkers and the Geo QA & CRS Inspector — a dropped geometry type is an error, a dropped property is a warning. The converted file is always available to download; this tool is about visibility into the trade-off, not gatekeeping the conversion. Nothing is uploaded; everything runs in your browser.
Nothing is uploaded — read and converted directly in your browser.
About this tool
Every geo format converter on the web ends the same way: "Conversion complete." That message is true and also incomplete — GPX has no polygon concept, KML keeps only a name and description per feature, WKT keeps no properties at all, and a plain CSV can only hold one point per row. None of that is a bug in any particular converter; it's an inherent limit of the target format, and it means a conversion can "succeed" while quietly leaving out exactly the data you needed. This tool doesn't try to predict that loss with a lookup table — it runs the real conversion (the same lib/geo/serializers logic the Geo Format Converter uses), reads the resulting file back in through the same parser a real import would use, and directly compares the result against the source: which geometry types disappeared, which property keys didn't survive, how the feature count changed. That comparison is exactly as accurate as actually opening the converted file and checking it yourself, just automatic. Findings are grouped the same way as the YOLO/COCO/Pascal VOC Dataset Health Checkers and the Geo QA & CRS Inspector — a dropped geometry type is an error (real data is gone), a dropped property is a warning (often expected, still worth seeing). The converted file is available to download either way — this tool doesn't block a conversion, it tells you exactly what you're trading away by doing it.
Supported formats
- GeoJSON (target) — Keeps everything — every geometry type and every property survives.
- KML (target) — Any geometry type is representable, but only a feature's "name" and "description" properties survive — every other property is dropped.
- GPX (target) — Polygon and MultiPolygon have no GPX equivalent and are dropped entirely; only "name" survives as a property.
- CSV (target) — Only Point and MultiPoint survive — a CSV row is one coordinate pair, so LineString and Polygon features are dropped. Every property survives as a column.
- WKT (target) — Every geometry type is representable, but WKT has no property mechanism at all — every property is dropped.
- Shapefile (source only) — Read via the same .prj-aware reprojection as the Geo QA & CRS Inspector and Geo Format Converter — not offered as a conversion target.
What you can do
- Convert GeoJSON, KML, GPX, CSV, WKT, or a Shapefile .zip to any of the five text formats
- See exactly what the conversion actually changed — not just "done"
- Flags geometry types the target format can't represent and properties it silently drops
- Nothing is uploaded — the file is read, converted, and checked entirely in your browser
How to use
Step 1
Pick a file and a target format
GeoJSON, KML, GPX, CSV, WKT, or a Shapefile .zip, converting to any of the five text formats.
Step 2
The conversion runs for real
Then the actual output is read back in and compared against the source — not guessed at.
Step 3
Review what changed
Dropped geometry types and dropped properties are grouped separately, worst first.
Example
A finding looks like this:
LOSS.GEOMETRY_TYPE_DROPPED
3 of 3 Polygon features couldn't be represented in GPX and were dropped.
Alongside it, LOSS.PROPERTY_KEY_DROPPED findings list every property key that didn't make it into the converted file — both are computed from the real converted output, not predicted from a table.
How your data is handled
This tool is labeled 🟢 Browser: your file is read directly via your browser's File API, converted, and compared entirely client-side — nothing is uploaded, and there's no server involved anywhere in this tool. No AI model is used; every finding comes from directly comparing the real conversion output against the source, not a prediction.
Frequently asked questions
Does this stop me from downloading a conversion that loses data?+
No — the converted file is available to download regardless of what the findings show. This tool is about visibility, not gatekeeping: you might already know GPX can't hold polygons and be fine with that; the point is that you know, rather than discovering it later.
How is this different from the Geo Format Converter?+
The Geo Format Converter is for a quick, everyday conversion with a basic "N features couldn't be represented" count. This tool is for when you specifically want to know what changed before trusting the result downstream — full geometry-type and property-level detail, not just a count.
Why is a dropped geometry type an error but a dropped property only a warning?+
A dropped geometry type means whole features are gone from the output — there's no way to get that data back from the converted file. A dropped property usually means one piece of metadata per feature is gone, which is real but often an acceptable trade-off (most people converting to KML don't need every custom field to survive, just the shape and a label).
My feature count went up after converting, not down — is that a bug?+
No — a few formats restructure rather than simply drop. A MultiPoint feature converting to CSV becomes several separate Point rows (a CSV row is one coordinate pair), so the feature count rises even though the underlying geometry type itself is still flagged as not directly representable.
Can I convert TO a Shapefile with this tool?+
Not currently — Shapefile is supported as a source (with the same .prj-aware reprojection as the Geo QA & CRS Inspector) but isn't offered as a conversion target here, matching the Geo Format Converter's scope.