Question 1

What is CBOR?

Accepted Answer

CBOR (Concise Binary Object Representation, RFC 7049 / RFC 8949) is a binary data serialization format based on JSON's data model. It is designed to be small in encoded size and efficient to encode/decode without schema negotiation. CBOR is widely used in IoT protocols (CoAP), COSE cryptographic tokens, and CBOR Object Signing and Encryption (JOSE) alternatives.

Question 2

What is MessagePack?

Accepted Answer

MessagePack is a binary serialization format that aims to be as compact as possible while preserving the JSON data model (null, boolean, integer, float, string, array, map). It is commonly used in Redis, Fluentd, and many RPC frameworks as a drop-in replacement for JSON with 20-50% smaller payloads and faster parsing.

Question 3

How do I read the hex or Base64 output?

Accepted Answer

The Encode direction converts your JSON to binary and displays it as uppercase hexadecimal (e.g. A4...) or Base64. To reverse the process, switch to Decode, paste the hex or Base64 string, and the tool reconstructs the original JSON. Both representations carry exactly the same bytes - hex is easier to inspect byte-by-byte while Base64 is more compact for transport.

Question 4

What does the compression ratio mean?

Accepted Answer

The compression ratio compares the binary payload size to the raw JSON byte length (UTF-8). A ratio below 1.0 means the binary encoding is smaller than the equivalent JSON. For example, 0.65 means the binary is 35% smaller. Numeric-heavy payloads typically compress the most; payloads dominated by short string keys may see little benefit.

outils gratuits pour développeurs web

CBOR / MessagePack Codec

JSON Input

Hex Output