Choosing the right data format affects API speed, developer experience, and client compatibility.
JSON
The default choice. Human-readable, lightweight, native to JavaScript, supported everywhere. Use for: REST APIs, web apps, configuration. Format with our JSON formatter.
XML
Verbose but powerful. Supports namespaces, validation schemas, and complex document structures. Use for: SOAP APIs, document formats, enterprise systems. Convert with JSON to XML.
CSV
Simplest format. Flat data only (no nesting). Use for: data exports, spreadsheet integration, bulk data transfer. Convert with CSV to JSON.
Protocol Buffers
Google's binary format. 3-10x smaller than JSON. Use for: high-performance APIs, mobile apps, microservice communication. Not human-readable — requires a .proto schema definition.