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JSON Merge Patch
Apply RFC 7396 merge patches locally, with null member deletion, recursive object merging and whole-array or scalar replacement.
JSON
JSON
Browser only
Runs locally in your browser. Your files, pasted content and generated output are not uploaded. Reset clears this tool’s working data.
This tool needs JavaScript. If it does not load, refresh the page and try again.
How to use this tool
- Paste Target JSON or choose its UTF-8 file; a selected file takes precedence.
- Paste Merge patch JSON or choose its separate UTF-8 file.
- Select Apply merge patch and download patched.json.
- Use null inside a patch object to delete a member. To replace an entire target, supply an array or scalar patch.
Examples
Target {"a":"b","c":{"d":"e","f":"g"}} with patch {"a":"z","c":{"f":null}} becomes {"a":"z","c":{"d":"e"}}.
Limitations
- Each input: 5 MiB UTF-8, 40 nesting levels and 200,000 values; selected files total at most 10 MiB. Result: 20 MiB with the same structural bounds.
- This implements JSON Merge Patch, not RFC 6902 JSON Patch operations. Arrays replace as complete values rather than merging item by item.
- Strict JSON and valid Unicode are required. Duplicate object keys are rejected; number-token spellings are retained without converting them to floating point.
- A null member in a patch object means deletion, so this syntax cannot use that member to assign a literal null value. No target URL or external document is fetched.
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