JSON Merge

Merge two JSON objects into one with deep merge and overwrite mode support.

How to Use

  1. Paste the first JSON object (JSON-A) into the left input box.
  2. Paste the second JSON object (JSON-B) into the right input box.
  3. Click the "Merge Two JSON" button. JSON-B's keys will overwrite JSON-A's values.
  4. The complete merged JSON result appears below.

Related Tools

JSON Diff

Compare differences between two JSON data objects
JSON Flatten

Flatten nested JSON into dot-notation path format.
JSON Editor

Visually edit JSON data with tree view expand/collapse support.

About JSON Merge

JSON Merge is a free online tool that merges two JSON objects into one. In daily development, we often need to merge default configurations with user configurations or combine data from multiple API responses.

During merging, when both JSON objects share the same key, JSON-B's values overwrite JSON-A's corresponding values. For nested objects, the tool performs deep merge, recursively processing each level of properties. Array-type values are replaced as a whole rather than concatenated. The entire operation runs locally in the browser without uploading data to any server.