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MapKmlTools

Simplify & Optimize KML Geometry

Reduce KML file size by optimizing geometry and removing redundant vertices. Free browser tool with no upload required for fast maps.
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Select KML/KMZ to simplify

or drag and drop them here

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Pro is Only 3$ per Month. Premium Tool Access, Ad Free, Bulk Conversion!
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What is Simplify KML?

High-resolution GPS tracks or detailed administrative boundaries often have too many points (vertices). This makes them slow to load in Google Maps or Google Earth.

This tool uses the Visvalingam-Whyatt algorithm to remove points that don't contribute significantly to the shape, drastically reducing file size while keeping the map looking accurate.

When Should You Use This Tool?

  • Your KML file is too big (e.g., >5MB) for Google My Maps.
  • Google Earth crashes or lags when loading your file.
  • You want to use a detailed border on a web map.

How to Use Simplify KML

  1. Upload a heavy KML file.
  2. Adjust the 'Tolerance' slider.
  3. Watch the vertex count drop (e.g. from 10,000 to 1,000).
  4. Verify the shape integrity on the map.
  5. Download the optimized file.

Frequently Asked Questions

Q:How do I reduce the size of a KML file?

Upload your KML or KMZ file, set a simplification tolerance (higher = fewer vertices = smaller file), and click Simplify. The tool uses the Douglas-Peucker algorithm to reduce redundant vertices while preserving the overall shape of your polygons and lines.

Q:Is KML Simplifier free to use?

Yes, simplifying and compressing KML files is 100% free with no account required.

Q:Does KML Simplifier upload my files to a server?

No. The vertex reduction runs entirely in your browser. No file data is sent to any server.

Q:Will it change the shape of my polygons?

Simplification removes redundant vertices while maintaining the overall shape. You control the tolerance — a low tolerance preserves more detail, a high tolerance produces smaller files with slightly smoothed shapes.

Q:How much can it reduce file size?

Reductions of 70–95% are typical for complex land area KML files. For detailed survey polygons with many closely-spaced vertices, you can often reduce from 50 MB to 2 MB with minimal visual difference.

Q:Does it support KMZ files?

Yes. You can upload .kml or .kmz files directly. The tool automatically decompresses KMZ, simplifies the geometry, and lets you download as either KML or KMZ.

Q:Will my lines look jagged?

If you simplify too much, yes. Use the slider to find the sweet spot between size reduction and visual smoothness.

Pro is Only 3$ per Month. Premium Tool Access, Ad Free, Bulk Conversion!
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