About The JSON Merge Patch Tool

The JSON Merge Patch Tool applies RFC 7396 merge patch documents to a base JSON object and previews the patched result.

The patch is applied locally in your browser. Use sanitized JSON when working with production configuration, API payloads, secrets, or customer records.

How to Apply a JSON Merge Patch Online

1. Paste the original object into the Base JSON document box.
2. Paste the patch object into the Merge patch JSON box.
3. Click Apply Merge Patch to preview the result.
4. Review removed keys, overwritten values, and nested object changes before copying the output.

Choosing Options Correctly

Patch object:
- Use object keys to add or replace values.
- Set a key to null when RFC 7396 should remove that key from the target object.

Arrays and primitives:
- Arrays are replaced as whole values, not merged item by item.
- A non-object patch replaces the target document with that patch value.

Common Use Cases

• Previewing API PATCH payload behavior.
• Testing configuration overrides before applying them.
• Explaining how null deletion works in merge patch.
• Comparing base and patched JSON during integration work.

Quick FAQ

Is this JSON Patch?
No. JSON Merge Patch is RFC 7396 and uses a partial object; JSON Patch is RFC 6902 and uses operation arrays.

Does null mean set a value to null?
In merge patch, null removes a member from an object. Use a different patch format if you must set a field to JSON null.

Does the base JSON change permanently?
No. The page produces a patched output; your pasted input stays editable.

What happens with arrays?
Arrays are replaced as whole values by merge patch. It does not merge individual array items.