geojson-vt

Fix a coordinate rounding change in v5.0.0 that could shift geometry by one pixel at maxZoom. Tile output at maxZoom now matches v4 again, with no impact on performance.

A rework of geojson-vt's internal data layout that cuts memory use roughly by 2–4 times on large datasets, with the same tile output.

Memory and performance

• Retained memory after building an index is 45–75% lower across the board (a 205 MB US counties GeoJSON now holds 103 MB instead of 241 MB).
• Peak memory during tile generation is 45–79% lower, so datasets that used to crash browser tabs now fit.
• Total allocation during build is 50–90% lower, meaning far less GC pressure.
• Build time for point datasets is 50–70% faster. Line and polygon datasets are within roughly 10% of v4 on default settings.

API changes

• Breaking: the default export is now a class. Replace geojsonvt(data, options) with new GeoJSONVT(data, options). The browser global is renamed from geojsonvt to GeoJSONVT.
• Breaking: getTile returns {features} only. Internal fields like numPoints, source, x, y, z are no longer exposed on the result.
• New getTileRaw(z, x, y) returns the tile as stored: flat [x, y, x, y, ...] typed arrays with no per-coordinate objects. Zero-copy, read-only, and much cheaper than getTile for renderers that can consume flat coordinates.
• TypeScript declarations ship with the package. Remove @types/geojson-vt if you have it installed.

Fixes

• A point lying exactly on a shared tile edge now appears in exactly one tile instead of both.
• Polygons straddling tile boundaries no longer produce degenerate single-vertex rings at high zooms.
• Empty parts in a MultiPolygon are skipped instead of breaking the feature.
• Geometries with missing coordinates throw the standard invalid-GeoJSON error instead of an opaque TypeError.
• Tile coordinates may differ from v4 by a single pixel in rare cases due to integer coordinate storage. Output is otherwise identical.

Fix an edge case where lines where sometimes clipped incorrectly when points coincided with tile edges (by @DeZhao-Zhang) #161

Fix handling of features with empty coordinates — treat them the same way as features with null geometry (as per the spec).

Fix issues in some ESM setups because of an incorrect exports field in package.json.

• ⚠️ Breaking: drop CommonJS entry point and switch to ESM only for Node & bundlers + UMD bundle for browsers. #180
• ⚠️ Breaking: drop support for IE11 (you can still transpile on your end to keep it). #180
• Fix a rare edge case that could potentially lead to stack overflow by @district10 in #173 and @mlptownsend in #176
• Small performance optimizations by @vicb in #133, #132, #135
• Force getTile arguments as number by @andrewharvey in #128
• Fix a minor bug in tiling code by @CraigglesO in #130

• Add generateId option for automatically filling feature id property (populating it with the index of the feature in a feature collection).
• Add promoteId option for filling feature id with a value from a specific feature property.

• Fix handling of features with id of 0. #107
• Minor fix for degenerate inputs.

Fixed a bug which caused a "max call stack size" error on certain degenerate input. #105

Fixed a bug with lineMetrics: true and MultiLineString geometries where only the first line was processed.

Fixed inconsistent clipping of features on tile boundary when buffer = 0. #102

• Added experimental lineMetrics: true option that adds mapbox_clip_start and mapbox_clip_end properties to all line features in the generated tiles, indicating which part of the original full line each feature represents.
• Turned GeoJSON-VT into a proper ES module (so you can do import geojsonvt from 'geojson-vt' in supported environments).

• Massively improved performance. Index now takes ~2x less memory and generating tiles is overall 20% to 100% faster (with bigger gains on heavier datasets).
• Removed "clipped square" heuristics (they were complicating the codebase without a noticeable performance gain).
• Added a descriptive error when passing zoom higher than 24.
• Added TopoJSON support to the demo page.

• Fixed support of feature id property.

• Improved tiling algorithm to avoid redundant clipping when tiles are requested in an empty area.
• Fixed issues with GeoJSON that only has data above 180 or below -180 longitude.

• Fixed ring winding order for polygons and multipolygons in accordance with vector tile specification 2.0.
• Fixed handling of features with null geometry (now ignored instead of throwing an error).

• Fixed a bug where getTile would initially return null when requesting a child of a solid clipped square tile.