About JSON Patch

Generate or apply RFC 6902 JSON Patch operations. Part of the DevTools Surf developer suite. Browse more tools in the JSON collection.

Use Cases

• Generate minimal update payloads for PATCH API endpoints
• Track configuration changes as auditable patch sequences
• Apply incremental updates to large JSON documents efficiently
• Build undo/redo systems using reversible patch operations

Tips

• Generate RFC 6902 patch operations from two JSON documents
• Apply a patch to transform a JSON document step by step
• Validate patch operations before applying to production data

Fun Facts

• RFC 6902 (JSON Patch) was published in April 2013, defining six operations: add, remove, replace, move, copy, and test.
• JSON Patch uses JSON Pointer (RFC 6901) for path references, where '/foo/0' means the first element of the 'foo' array.
• The 'test' operation in JSON Patch acts as a precondition check, failing the entire patch if the expected value does not match.

FAQ

What is a JSON Patch?

A JSON document describing a sequence of changes (add, remove, replace, move, copy, test) to apply to another JSON document. Defined in RFC 6902 and widely used in REST APIs and CRDTs.

Can I generate a patch from two JSON files?

Yes — paste the 'before' and 'after' documents and the tool emits a patch that transforms one into the other. Paste the patch and a source document to apply it.

What's the difference between JSON Patch and JSON Merge Patch?

JSON Patch is an array of operations — precise but verbose. JSON Merge Patch (RFC 7396) is simpler: it looks like a partial JSON document. Use Merge Patch for simple updates, JSON Patch for moves, removals, and conditional replacements.

Does it validate patches before applying them?

Yes. If a 'test' operation fails or a path doesn't exist, the tool reports the error instead of producing a corrupt result.