Data converter · runs 100% in your browser

JSON to BSON Converter

Serialize JSON documents to MongoDB's binary BSON format directly in your browser. Accepts a single document or an array — arrays are emitted as a BSON document stream. Extended JSON syntax is supported for typed values.

No uploadNo signupNo trackingFree, unlimited
Drop your JSON file here
or click to choose a file

How to use

  1. Drop your JSON file (or click to browse).
  2. The converter parses the file locally in your browser.
  3. BSON output is built in memory and offered for download.
  4. Click Download to save the BSON file.

FAQ

Does my data file upload to a server?

No. Conversion runs entirely in your browser using WebAssembly and Web APIs. Open the Network tab in DevTools while you convert — you'll see no outbound traffic carrying your file.

Is this really free?

Yes. No signup, no quota, no upgrade tier. The conversion runs on your machine, so it costs us nothing to host.

Is there a file size limit?

Browser memory is the only ceiling. On a modern desktop browser, a few hundred megabytes works fine. Mobile devices have tighter limits.

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