Flatten JSON

Convert nested objects to flat dot-notation keys (key.subkey).

About the JSON Flattener

The JSON Flattener converts nested objects into a single level using path-style keys, e.g. {"a":{"b":1}} becomes {"a.b":1}. It is useful because flat structures are easier to map to CSV columns, database fields, form data, and analytics events.

Like every Pockly tool, it runs entirely in your browser: the JSON you paste is processed on your device and never uploaded to a server.

How to use it

  1. Paste your JSON into the input panel.
  2. The result appears automatically in the output panel.
  3. Fix any reported errors and re-run if needed.
  4. Copy the result with one click.

Frequently asked questions

Is my JSON uploaded anywhere?
No. Processing happens locally in your browser; your data never leaves your device.
Is there a size limit?
No fixed limit. Documents of several megabytes are processed in seconds.
What if my input is not valid JSON?
The tool shows a clear error message with the location of the problem instead of failing silently.
Are the other JSON utilities related?
Yes — format, minify, sort, validate, flatten, diff, and query all work together; you can chain them by copying output from one into another.