CBOR is binary JSON under an IETF standard (RFC 8949) — same data model, a fraction of the size, used by COSE, WebAuthn and IoT devices.
Typical use: Decode CBOR to JSON to inspect what a device or token actually sent.
About the CBOR format
CBOR (RFC 8949) is what happens when JSON decides to stop wasting bytes: the same objects, arrays, strings and numbers, but length-prefixed binary instead of text. It is the credential format inside WebAuthn passkeys, the payload format of COSE signing and a favourite of embedded devices that cannot afford verbose JSON.
Decoding CBOR to JSON is the everyday debugging move: dump what a token, sensor or authenticator actually sent, then read it like ordinary JSON. The mapping is lossless for the data model both formats share.
Strengths
- ✓ IETF standard with a strict data model
- ✓ Much smaller than equivalent JSON
- ✓ Round-trips to JSON without data loss
Limitations
- ✗ Not human-readable without a decoder
- ✗ Fewer tools speak it than JSON
- Structure
- Binary tagged values
- Types / schema
- Numbers, strings, arrays, maps
- Compatibility
- WebAuthn, COSE, IoT
- Best for
- Compact machine-to-machine data
Convert CBOR to…
5 direct directions, sorted A–Z; 🔥 marks popular targets.
Convert other files to CBOR…
Frequently asked questions
What is a CBOR file?
CBOR is binary JSON under an IETF standard (RFC 8949) — same data model, a fraction of the size, used by COSE, WebAuthn and IoT devices.
How do I convert CBOR files online?
Pick a target format from the "Convert CBOR to…" list below, drop your file and hit convert. Everything runs in your browser — no install, no upload, no watermark, no limits.
Is it safe to convert CBOR files here?
Yes. Every conversion is performed by your own device inside the browser — files never leave for a server, and the page keeps working even offline.
Which formats can CBOR convert to?
This page lists all 5 directions across documents, images, audio, video, spreadsheets and archives — each one is its own free converter page.