Apply a JSON Merge Patch to a document and preview the merged result.
Type or paste on the left — the result updates as you type.
RFC 7396: null deletes a property, arrays replace whole arrays, and a non-object patch replaces the document. No prototype properties are executed.
Up to 100,000 UTF-16 units per input and 1,000,000 per result. See the supported formats and examples below.
Tool page updated: 2026-09-27
