“Style JSON” files that define map design developed around the Mapbox Style Specification. Today, related specifications include the open-source MapLibre Style Specification and the Geospatial Information Authority of Japan’s GSI Maps Vector style specification. This article compares them using Mapbox as the baseline.
Historical Background
The modern style JSON format originated with Mapbox’s Mapbox Style Specification in the mid-2010s. It appeared alongside Mapbox GL JS and became a de facto standard for dynamic WebGL-based map rendering.
After Mapbox GL JS v2 changed licensing, the MapLibre project forked Mapbox GL JS v1 and continued open-source development. In Japan, the Geospatial Information Authority of Japan (GSI) also created a related style format for GSI Maps Vector.
Main Timeline
| Year | Event |
|---|---|
| 2013 | Mapbox introduced vector tile technology in products such as Mapbox Streets. |
| 2014 | Mapbox announced Mapbox GL and style JSON-based rendering. |
| 2019 | GSI released a trial version of GSI Maps Vector. |
| 2020 | GSI began nationwide vector data provision. |
| 2020 | Mapbox GL JS v2 moved away from the previous open-source license. |
| 2021 | MapLibre was launched as an open-source fork of Mapbox GL JS v1. |
Mapbox Style and GSI Style
| Aspect | Mapbox Style Specification | GSI Maps Vector Style | Notes |
|---|---|---|---|
| Basic structure | JSON with version, sources, layers, sprite, glyphs | JSON-like hierarchy with group, directory, item, layer, draw | GSI adds hierarchical grouping |
| Layers | Listed in a layers array | Layers are grouped under UI-oriented structures | GSI aligns with its map interface |
| Layer types | fill, line, symbol, circle, raster, background, etc. | Similar basic draw types | 3D support is more limited |
| Paint properties | paint and layout | Properties under draw such as color and weight | GSI simplifies many definitions |
| Filters | Mapbox expressions | Similar but more limited | Compatibility varies |
| Draw order | Array order | zIndex | GSI uses explicit numeric ordering |
| Extensions | None in the baseline | additional-filter, blend, editZIndex, etc. | Optimized for Japanese administrative map needs |
Mapbox Style and MapLibre Style
| Aspect | Mapbox Style Specification | MapLibre Style Specification |
|---|---|---|
| Structure | version, sources, layers, sprite, glyphs | Same basic structure |
| Purpose | Mapbox commercial platform | Open-source compatible implementation |
| Compatibility | Follows Mapbox’s platform direction | Preserves compatibility from the v1 fork |
| Governance | Mapbox-led | Community-led under MapLibre |
| Expressions | Advanced expression syntax | Largely compatible expression syntax |
| 3D features | Includes features such as terrain, sky, and fog | Support depends on implementation progress |
| License context | Mapbox commercial ecosystem | BSD-style open-source ecosystem |
Summary
GSI style extends the Mapbox-influenced structure for Japanese administrative and cartographic needs, including hatching and hierarchical UI grouping. MapLibre style preserves a Mapbox-compatible open-source path. All three are related, but they serve different institutional and technical goals.