JSON Merge

• JSON Formatter
• JSON Sort Keys
• JSON Diff
• JSON Tools

Merge two JSON objects into one: a base (JSON 1) and an overlay (JSON 2). Overlay keys overwrite base; with deep merge, nested objects are merged recursively. Paste or upload each side; invalid input shows which side failed, a snippet, and links to the Formatter and Validator. Clear resets both inputs and output. Choose indent 2 or 4 spaces. Download or copy the result. All processing is client-side.

• Shallow or deep merge: Shallow: only top-level keys; overlay overwrites base for each key. Deep: nested objects are merged recursively so you can combine configs without losing nested keys.
• Error handling: Invalid JSON in either input shows which side (base or overlay) failed, the parser message, and when available a snippet. Links to Formatter and Validator help you fix the input.
• Clear: One click clears both text areas, the merged output, and file inputs so you can start with new JSON.

Powered by browser APIs and client-side processing.

Configs and API payloads often need to combine a default object with overrides. Merging two objects gives one result where overlay values take precedence; deep merge does the same for nested objects so you can layer defaults and environment-specific settings. Running the merge in the browser keeps your data private and works offline after the page loads.

• JSON 1 (base): The first object. Paste or upload a .json file.
• JSON 2 (overlay): The second object. Keys here overwrite base. Paste or upload.
• Deep merge: When checked, nested objects are merged recursively. When unchecked, overlay keys replace base keys at the top level only.
• Indent: 2 or 4 spaces for the merged output.
• Clear: Clears both inputs, output, any error, and file inputs.