JSON to MessagePack Converter
Encode JSON values as a downloadable MessagePack binary file with finite-number and depth checks.
Your input is sent to this site only after you choose Convert on server. The conversion runs for this request and no history is saved. Upload up to 4 MiB combined; Office files have a 2 MiB limit.
Enter your text
Edit the example text or paste your own content.
How to use JSON to MessagePack Converter
- Load the example or paste your own input.
- Review the settings, then select Convert on server to send input for processing.
- Review the result, then copy or download it.
What this tool helps you do
Prepare a small binary payload for a system that accepts MessagePack instead of textual JSON. Objects, arrays, strings, booleans, null and supported numbers retain their JSON meaning while the encoder chooses appropriate MessagePack representations. The result is a binary file for download, not a Base64 string or a simulated size estimate.
Format rules and limitations
Only JSON values are accepted; this tool does not infer dates, binary buffers or application-specific extension types from strings. Integral numbers outside JavaScript’s safe range are rejected, so preserve large identifiers as strings. Nesting is limited to 32 levels and total text to 2 MiB. MessagePack interoperability can depend on the receiving implementation’s type expectations; compare the decoded structure before using a payload in an integration.
Example input
{"name":"Ada","active":true,"scores":[3,5,8]}What should I check before relying on the output?
Only JSON values are accepted; this tool does not infer dates, binary buffers or application-specific extension types from strings.
Is input uploaded?
This tool sends input to this site’s conversion API after you select Convert on server. Files use bounded workers and, when needed, private temporary folders deleted after processing or cancellation. No conversion history is saved. The converter does not upload files to a third-party conversion service.