What this tool does
It accepts hex dumps or Base64 text and decodes common MessagePack primitives, arrays, maps, binary blobs, and strings.
It converts decoded values into formatted JSON so event payloads can be reviewed next to JSON tooling.
It reports byte-level parse errors when a MessagePack payload is malformed or truncated.
It keeps event samples local, which is important for backend queues, streams, and service-to-service payloads.
Typical use cases
- Inspect a MessagePack event captured from a test queue or fixture.
- Convert a small binary payload into JSON for a debugging note.
- Verify whether a Base64 blob is valid MessagePack before handing it to another tool.
- Document malformed payload errors with a minimal byte sample.
- Bridge binary event samples into JSON Formatter or JSON Diff workflows.
Input examples
Hex MessagePack
82 a2 69 64 01 a4 6e 61 6d 65 a5 41 6c 69 63 65
Output examples
Decoded JSON
{
"id": 1,
"name": "Alice"
}Parse error
Unexpected end of MessagePack input while reading map value.
Common errors and fixes
Odd-length hex input
Remove separators carefully and ensure every byte has two hex digits.
Input is Base64 but hex mode is selected
Switch to Base64 mode before decoding.
Expecting Protobuf or Avro support from MessagePack
MessagePack can be decoded without a schema; schema-based formats need separate tooling.
Security and privacy notes
For the shared privacy terminology, local processing model, external-request labels, and DevTools verification workflow, see the Trust Center.
- Decoding runs in the browser and does not upload event payloads.
- Binary payloads can contain tokens, emails, and private identifiers after decoding.
- Copy only scrubbed JSON excerpts into shared tickets or docs.
Step-by-step workflow
- Feed MessagePack Inspector the smallest reproducible sample you can collect from the real issue.
- Review the first findings and separate confirmed signals from assumptions or environment-specific noise.
- Compare a clean baseline sample against the problematic input when you need to isolate regressions.
- Keep one redacted output snapshot with the key findings for tickets, runbooks, or incident handoff.
Quality checklist before sharing output
- Confirm MessagePack Inspector findings still reproduce with the same input and assumptions.
- Check that the sample includes enough surrounding context to support the conclusion you are drawing.
- Translate notable findings into concrete next checks, ownership, or remediation notes.
- Redact private hosts, tokens, certificates, or customer identifiers before sharing analysis output.
Operational notes
MessagePack Inspector is most effective when it produces a focused, reproducible evidence bundle that can be handed to the next engineer without extra cleanup.
Related tools
JSON Formatter
Format, validate, and minify JSON payloads instantly.
Hex/Bytes Workbench
Inspect text, hex, and Base64 as bytes locally with UTF-8 text, grouped hex, Base64, binary rows, offsets, and byte statistics.
Base64 Encode/Decode
Encode text to Base64 format or decode it back to a readable string.
JSON/YAML/TOML Converter
Convert JSON, YAML, and TOML configuration data locally in your browser.
Frequently asked questions
Does MessagePack need a schema?
No. MessagePack is self-describing enough for this inspector, unlike Protobuf or many Avro workflows.
Can I download the decoded output?
The page supports copying the formatted JSON; use the browser copy action for reviewed excerpts.
What happens on invalid binary input?
The decoder returns an actionable parse error instead of showing stale output.
