KML Viewer and Validator

How to use

1. 1Pick Paste KML to type or paste a document, or Upload .kml file to drop a file from your machine.
2. 2Read the verdict banner for a pass / fail signal, the placemark and position counts, and any KML 2.2 errors or warnings with the exact path inside the document.
3. 3Inspect the SVG preview to confirm the geometry plots where you expect: points are amber, lines are green, polygons are blue with even-odd fill for inner-ring holes.
4. 4Open the Document summary, Geometry types, and Folders panels to see the KML version, the bounding box, the type breakdown, and the per-folder placemark count.
5. 5Use Copy as GeoJSON to grab a FeatureCollection ready for Mapbox, Leaflet, MapLibre, or PostGIS, Copy positions CSV to extract every longitude, latitude, and altitude to a spreadsheet, or Copy Formatted KML to grab a re-indented version of the document.
6. 6Try Load valid sample for a Manhattan landmarks document, or Load broken sample to see how the validator reports out-of-range coordinates, an unclosed Polygon ring, and a Placemark that is missing geometry.

About this tool

KML Viewer and Validator parses any KML document (the XML format Google Earth, Google My Maps, ArcGIS, QGIS, Garmin BaseCamp, drone planners, and most consumer mapping apps export), checks it against the OGC KML 2.2 standard, previews every Placemark on an inline SVG map, and converts the whole document to GeoJSON, a flat positions CSV, or a re-formatted KML string. The parser uses the browser's native DOMParser to read the XML safely, then walks every <Document>, <Folder>, nested folder, and <Placemark> to extract <Point>, <LineString>, <Polygon>, and <MultiGeometry> elements. Coordinate text is split on whitespace and parsed as a comma-separated tuple of longitude, latitude, and optional altitude (the KML order, which is the opposite of latitude / longitude that many people expect), and every value is validated against the -180 to 180 longitude and -90 to 90 latitude range with finite-number checks. LinearRings inside <Polygon> are verified for the minimum four positions and the closing-position requirement, and inner rings (holes) are projected into the GeoJSON output. Every issue is reported with an XML breadcrumb-style path like 'kml > Document > Folder[1] > Placemark[3] > Point > coordinates' so a GIS analyst can jump straight to the bad value. The SVG preview projects every geometry to the same bounding box using an equirectangular projection around the centre latitude so the picture stays usable from tropics to polar caps, with points drawn amber, lines green, and polygons blue with an even-odd fill that respects holes. Document-level summaries report the KML schema version (parsed from the xmlns attribute), the document name, the placemark count, the folder count, the bounding box in longitude and latitude, the geometry-type breakdown (Point, LineString, Polygon, MultiGeometry), and a per-folder placemark count so deeply nested My Maps exports are easy to inspect. The GeoJSON export builds a FeatureCollection with one Feature per Placemark, carries the name, description, styleUrl, and folder path into Feature.properties, and maps KML MultiGeometry to the GeoJSON GeometryCollection. The CSV export emits one row per Position with the placemark index, placemark name, folder path, geometry kind, ring index, position index, longitude, latitude, and altitude, ready to load into Excel, Google Sheets, Pandas, or PostGIS. .kmz files are detected by their ZIP signature; this tool stays dependency-free, so the user is asked to unzip and upload the inner doc.kml. Everything runs locally in your browser; the file you paste or drop in is never uploaded, which matters when you are reviewing client routes, restricted survey areas, or any geographic data that should not leave your device.

Free to use. Works in your browser. No signup, no login.