Toolsly
Merger

JSON Merge

Combine two JSON objects with a deep recursive merge. Choose whether the right or left side wins on conflicting scalars, and whether arrays at the same path should be concatenated or replaced. Useful for layering config files, applying overrides on top of defaults, or building composite payloads. Runs entirely in your browser — free, online, no upload.

Privacy

Runs entirely in your browser — nothing is sent to any server.

Cost

Free. No sign-up, no watermark.

Type

Merger

Tools that work with the same formats — most users open one of these next.

Frequently asked

Is JSON Merge free to use?

Yes. JSON Merge is completely free with no sign-up, no watermark, and no usage limits. Toolsly does not charge for any of its tools.

Do my files and data stay private?

Yes — JSON Merge runs entirely in your browser using your device's CPU. Files and text are never uploaded to our servers, so your data stays private.

How does JSON Merge work?

Open JSON Merge, paste or fill in the input fields, and the result updates instantly. Everything runs in your browser — no upload, no waiting.

Which browsers does JSON Merge support?

Any modern browser works — Chrome, Firefox, Safari, and Edge on desktop and mobile. JSON Merge uses standard web APIs and does not require any plugin, extension, or sign-up.