What is CBOR Inspector?
CBOR Inspector decodes and encodes Concise Binary Object Representation (CBOR) data, a binary format defined in RFC 8949. CBOR is designed for small message sizes and extensibility, making it popular in IoT protocols, WebAuthn/FIDO2 authentication, COSE signatures, and constrained device communication.
Unlike JSON, CBOR supports binary byte strings, tags for semantic meaning, and deterministic encoding. This makes it powerful but harder to inspect manually. DevKit’s CBOR Inspector converts raw bytes into the standard diagnostic notation, providing a human-readable view of every major type, tag, and value in the data.
How to Use CBOR Inspector
Paste CBOR data as hex bytes or Base64 into the input editor. Tap Decode to parse the binary and display the result in CBOR diagnostic notation, a text format that looks similar to JSON but includes CBOR-specific constructs like tags (0("2023-01-01")) and byte strings (h'48656C6C6F').
The tree view shows each CBOR item with its major type, additional info byte, and decoded value. Maps and arrays can be expanded to explore nested structures. Tags are displayed with their semantic meaning when recognized (e.g., Tag 1 for epoch timestamps, Tag 24 for embedded CBOR).
To encode, switch to encode mode and write CBOR diagnostic notation. The tool generates the corresponding binary, displayed as hex or Base64.
Common Use Cases
- WebAuthn/FIDO2 debugging: Decode CBOR-encoded attestation objects and authenticator data from FIDO2 registration and authentication flows.
- IoT protocol inspection: Inspect CBOR payloads from CoAP, LwM2M, or MQTT-SN messages in constrained device networks.
- COSE signature analysis: Decode COSE_Sign1 and COSE_Encrypt structures used in mobile driver licenses, health credentials, and secure messaging.
- Embedded development: Verify CBOR encoding output from resource-constrained devices during firmware development and testing.
- Standards compliance testing: Validate CBOR data against expected structures during protocol implementation and interoperability testing.