View GIS Files Without Leaving VS Code: Meet Geo Data Viewer Fast

View GIS Files Without Leaving VS Code: Meet Geo Data Viewer Fast

If you work with geospatial data, you know the drill: download a Shapefile, switch to QGIS, wait for it to load, inspect the data, switch back to your code editor. That context switch kills momentum—especially when all you needed was a quick look at the geometry or a sanity check on the attributes.

Geo Data Viewer Fast eliminates that round-trip. It opens geospatial files in an interactive Kepler.gl map panel right inside VS Code. No desktop GIS launch, no browser tab, no file upload. Just open the file and see the map.

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What It Does

Geo Data Viewer Fast is a VS Code extension that renders local geospatial files in an interactive map webview powered by Kepler.gl. The workflow is deliberately minimal:

1. Open a supported file in VS Code
2. Run the preview command (or press Ctrl/Cmd + Alt + M)
3. The map appears in a side panel

That’s it. No configuration, no server, no upload.

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Supported Formats

The extension covers the formats GIS developers encounter most often:

Format	Extensions
GeoJSON / JSON	.geojson, .json
Kepler.gl configs	.map.json, .kgl.json
TopoJSON	.topojson, .topo.json
CSV / TSV	.csv, .tsv
Excel	.xlsx
KML	.kml
GPX	.gpx
GML	.gml
IGC (paragliding logs)	.igc
WKT	.wkt
Shapefile	.shp, .zip
FlatGeobuf	.fgb
GeoParquet	.parquet, .geoparquet, .gpq
PMTiles	.pmtiles

That’s 15 format families—enough to cover the vast majority of vector geospatial data you’ll encounter in development, ETL pipelines, or data science workflows.

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Key Features

Kepler.gl Rendering

The extension uses Uber’s Kepler.gl as its rendering engine, which means you get the same high-quality visualization layers available in the standalone Kepler.gl app: point maps, arcs, hexbin heatmaps, 3D building extrusions, and timeline animations. The difference is that it all happens inside VS Code.

Adapter-Based Parser Pipeline

Each format has its own dedicated parser adapter. This architecture makes the extension easier to maintain and extend—adding a new format means writing one adapter, not refactoring a monolithic loader. The adapter chain also enables format-specific optimizations (e.g., streaming FlatGeobuf bounds instead of loading the entire file).

PMTiles Vector Preview

PMTiles is increasingly popular for cloud-native vector tile hosting. Geo Data Viewer Fast supports PMTiles files directly, with native Kepler.gl hover/click interaction on vector tile features. This is useful for inspecting tilesets locally before deploying them to production.

Built-In Map Gallery

The extension ships with a curated gallery of sample datasets and Kepler.gl configs—Chicago bike routes, USA airports, world cities, major rivers, and more. It’s a quick way to test the extension or explore what Kepler.gl can do without hunting for sample data.

Run Geo Data Viewer: Map Gallery or press Ctrl/Cmd + Alt + G.

Large-File Safeguards

Previewing a 500,000-row CSV inside a VS Code webview is a recipe for a frozen editor. The extension implements a configurable row limit (geoDataViewer.largeFilePreviewLimit, default 5,000) that loads a representative sample instead of blocking the UI. You can adjust or disable the limit in your settings.

Parse Cache

The in-memory parse cache avoids re-parsing unchanged files on repeat previews. It’s on by default and includes a diagnostic mode (geoDataViewer.showCacheDiagnostics) so you can verify cache hit/miss behavior.

Remote URL Support

Beyond local files, you can open geospatial data from HTTP/HTTPS URLs via Geo Data Viewer: Open from URL or Path (Ctrl/Cmd + Alt + U). The file is cached locally and then previewed—no persistent server dependency.

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How It Fits Into Your Workflow

The “Quick Inspection” Loop

The most common use case is the one that previously required a full context switch:

You receive a Shapefile from a colleague.
→ Open the .shp in VS Code
→ Ctrl/Cmd + Alt + M
→ Inspect geometry and attributes in the map panel
→ Close the panel, continue coding

Total time: under 10 seconds. No QGIS, no ArcGIS, no browser tab.

Data Pipeline Development

If you’re building ETL pipelines that transform geospatial data, the extension gives you an instant visual check at each stage of the pipeline. Write a transformation script, save the output, preview it in VS Code, iterate. The parse cache speeds up the loop when you’re only changing downstream logic.

Tileset Validation

Working with PMTiles or FlatGeobuf? Preview the tiles directly in VS Code before pushing them to a CDN or tile server. The Kepler.gl interaction model (hover tooltips, click-to-inspect) works on PMTiles vector features just like it does on GeoJSON.

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When to Use the Extension vs. GeoDataViewer.com

Geo Data Viewer Fast and GeoDataViewer are complementary tools in the same ecosystem. Here’s how to decide:

Need	Use
Quick preview of a local file while coding	VS Code extension
Format conversion (Shapefile → GeoJSON, KML → GeoPackage, etc.)	GeoDataViewer.com
Inspecting 20+ formats including FIT, DXF, XLSX	GeoDataViewer.com
Kepler.gl config preview and iteration	VS Code extension
PMTiles local preview	VS Code extension
Attribute table, field statistics, feature details	GeoDataViewer.com
Distance/area measurement, elevation lookup	GeoDataViewer.com
No install, browser-only access	GeoDataViewer.com
Integrated into your dev environment	VS Code extension

The rule of thumb: if you’re already in VS Code, stay in VS Code. If you need deeper inspection, format conversion, or you’re not at your development machine, use the browser.

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Installation

Install directly from the VS Code Marketplace:

1. Open VS Code
2. Press Ctrl/Cmd + Shift + X to open the Extensions panel
3. Search for “Geo Data Viewer Fast”
4. Click Install

Or install from the command line:

code --install-extension Ayamap.geo-data-viewer-fast

Or browse the marketplace listing directly.

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Configuration

Setting	Type	Default	Description
geoDataViewer.mapStyle	string	positron	Basemap style (positron or darkmatter)
geoDataViewer.largeFilePreviewLimit	number	5000	Max rows/features loaded in preview mode
geoDataViewer.enableParseCache	boolean	true	In-memory parse caching
geoDataViewer.showCacheDiagnostics	boolean	true	Show cache hit/miss diagnostics
geoDataViewer.enablePerformanceLog	boolean	false	Emit parse timing to output channel
geoDataViewer.mapboxToken	string	""	Optional Mapbox token for Kepler.gl

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Commands

Command	Shortcut	Description
Geo Data Viewer: Open Current File	Ctrl/Cmd + Alt + M	Preview the active file
Geo Data Viewer: Map Gallery	Ctrl/Cmd + Alt + G	Open sample dataset gallery
Geo Data Viewer: Open from URL or Path	Ctrl/Cmd + Alt + U	Load from URL or local path
Geo Data Viewer: Reload Map	—	Refresh current preview

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Architecture Notes

The extension is built around a few clean layers:

• Extension host (src/extension/): VS Code commands, gallery wiring, panel lifecycle
• Data layer (src/data/): Adapter-based format parsers, one adapter per format
• Webview (src/webview/): HTML shell, message bridge, panel state persistence
• Runtime assets (media/): Kepler.gl runtime and webview-side loaders

This separation makes the extension straightforward to extend. If you need to add support for a new format, you write a parser adapter—no changes required in the webview or extension host layers.

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What’s Next

The extension is actively maintained and evolving. Areas of ongoing development include:

• Additional format adapters based on community demand
• Tighter integration with GeoDataViewer’s format conversion engine
• Enhanced Kepler.gl layer configuration within the webview
• Performance tuning for very large datasets

If there’s a format or feature you’d like to see, open an issue or leave feedback on the marketplace listing.

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TL;DR

• What: A VS Code extension that previews 15+ geospatial file formats in an interactive Kepler.gl map panel
• Why: Stop switching to QGIS or a browser just to inspect a Shapefile
• How: code --install-extension Ayamap.geo-data-viewer-fast
• Shortcut: Ctrl/Cmd + Alt + M to open, Ctrl/Cmd + Alt + G for the gallery
• More formats & conversion: geodataviewer.com for browser-based viewing and 19-format inter-conversion