How to use GeoJSON Geometry Simplifier: practical workflow and checks
Use a real example to prepare input, run GeoJSON Geometry Simplifier, verify output, understand privacy, and respect current boundaries.
When to use it
Reduce line and polygon coordinates by tolerance, compare size, and download simplified GeoJSON. Simplification is useful for web display and transfer, not cadastral, legal, or precision boundaries. Tolerance uses current CRS units.
Practical example
For a coastline with 80,000 vertices, start with a tiny tolerance and compare count, size, bays, and island holes. Never replace a legal boundary with the simplified copy.
Steps
- Choose GeoJSON and record original features, vertices, and size.
- Enter a small tolerance appropriate to CRS units.
- Compare original and simplified bounds, corners, holes, and intersections.
- Download a copy after accepting the error; never overwrite the source.
Checks after completion
- Reduces web-map payload
- Instant vertex and size comparison
- Processing runs in this browser tab; the file is not uploaded to FreeTool to perform the task.
Do not rely on a success message alone. Sample counts, fields, dimensions, coordinates, text, or visual output against the source. Production, scientific, business, rights-sensitive, or formal deliverables require validation in the receiving system.
Current boundaries
- Geometry changes, so legal or precision boundaries are unsuitable
- Geographic tolerance is degrees, not meters
- Invalid polygons and topology gaps are not automatically repaired
Privacy and safety
Local files are processed in the browser tab and are not uploaded to FreeTool to perform the task. IIIF/DZI URLs are requested directly by the browser and remain subject to source logs, CORS, and access policy. Clear downloads, screenshots, and clipboard data after a shared device.
Common questions
What tolerance should I use?
Confirm CRS units, start very small for longitude/latitude, and review at the intended map scale.
Why do adjacent polygons develop gaps?
Per-feature simplification does not preserve shared topology; use a topology-aware GIS workflow.
Is data uploaded?
Processing runs in this browser tab; the file is not uploaded to FreeTool to perform the task.