twineconvert

free · in-browser · no upload

GeoJSON to WKB
Converter

Drop your GeoJSON file. We'll convert it to WKB right here in your browser, your file never leaves your device.

or drop your file

Select your file here to get started

or drop your file here.

Accepts .geojson, .json

nothing uploaded no file size cap no signup

How it works

Three steps. No upload, no signup.

  1. 1

    Drop your file

    Click the dropzone above or drag a GeoJSON from your desktop. Files of any size, there's no upload, so there's no upload limit.

  2. 2

    Convert in your browser

    The conversion runs entirely in this tab using JavaScript and WebAssembly. Your file never touches our servers, we don't have any.

  3. 3

    Download

    Get your WKB the moment the conversion finishes. Convert another, or close the tab.

Files stay on your device

Your file is never uploaded. The entire conversion runs in your browser using WebAssembly. We can't see what you convert because we have no server to see it.

No file size limit

Server converters cap free users at 1-2 GB and gate larger files behind a paid plan. Since nothing uploads, our limit is whatever your browser can handle.

Free, no signup, no ads on conversions

No account required. No watermark on the output. No queue. Drop a file, get a converted file.

Why convert GeoJSON → WKB

What this conversion is actually for

WKB is the compact binary encoding spatial databases use natively. If you want to bulk-load geometries into PostGIS via COPY (the fast path), you need WKB hex strings, not text WKT. This converts GeoJSON to raw binary WKB; pipe the output through xxd if you want hex.

A real example

You have a parcels.geojson and want to populate a PostGIS table at maximum speed. Convert to WKB and use COPY parcels (geom) FROM stdin (FORMAT binary).

Troubleshooting

Output is one geometry but my input had hundreds.

WKB is a single-geometry encoding. For batch loads, iterate the input FeatureCollection in your script and convert each geometry separately, or use the WKT export and ST_GeomFromText.

Formats involved

About GeoJSON and WKB

GeoJSON, Geographic JSON (RFC 7946)

GeoJSON encodes geographic features (points, lines, polygons) as JSON objects following RFC 7946 (2016). Coordinates are always [longitude, latitude] in WGS84. Supported natively by Leaflet, Mapbox GL, OpenLayers, ArcGIS, QGIS, and PostGIS — the default exchange format for web mapping. Lighter and easier to inspect than KML or shapefile (.shp).

How to open

GitHub renders GeoJSON files inline as interactive maps. geojson.io provides an in-browser editor + validator. QGIS opens .geojson directly. Leaflet/Mapbox apps consume it programmatically.

Full GeoJSON format guide →
WKB, WKB

WKB is a file format we support converting. Detailed format information is being added, for now, drop your file in the converter above and you'll get the conversion you came for.

How to open

Most operating systems open this format with a default application; if not, search for a free reader/viewer for the format.

Full WKB format guide →

You may also need

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Convert your GeoJSON to other formats

FAQ

Common questions

Is this GeoJSON → WKB converter really free?

Yes. No signup, no watermark, no daily file count limit. Every conversion runs in your browser, your file never touches our servers because there are no servers.

Where does my file go when I convert it?

Nowhere. The conversion runs entirely in your browser using JavaScript and WebAssembly. Your file is never uploaded to our servers. We don't have any servers handling files, there's nothing for us to log, store, or accidentally leak.

What's the maximum file size?

Whatever your browser can hold in memory. Practically, this means a few hundred MB on most computers, significantly larger than the 1-2 GB caps that server-upload converters charge for. Very large files (multi-GB) may require closing other browser tabs first.

Why convert GeoJSON to WKB?

Web mapping data exchange (Leaflet, Mapbox, ArcGIS). File interchange. The most common reason to convert is compatibility, WKB works in places where GeoJSON doesn't, or vice versa.

How do I open a GeoJSON file in the first place?

GitHub renders GeoJSON files inline as interactive maps. geojson.io provides an in-browser editor + validator. QGIS opens .geojson directly. Leaflet/Mapbox apps consume it programmatically.

Does this work offline?

Once the page is loaded, the conversion itself runs entirely offline. The first time you use a tool, your browser downloads the conversion library (a one-time cache). If you reload while offline, the page won't load, but you can install the site as a Progressive Web App for full offline use.

Can I convert multiple files at once?

Single file at a time for now. Batch conversion is on the roadmap, for now, drop one file, download the result, then convert the next.