Toolsly
Transformer

JSON Flatten

Paste a nested JSON object or array and produce a single-level (flat) object where each leaf value is keyed by its full path. Choose between dot-notation (`a.b.0`), underscore (`a_b_0`) or array-bracket (`a.b[0]`) styles. Useful for spreadsheets, env-var generation or quick diffs across structurally similar 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

Transformer

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

Frequently asked

Is JSON Flatten free to use?

Yes. JSON Flatten 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 Flatten 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 Flatten work?

Open JSON Flatten, 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 Flatten support?

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