How are arrays handled?

Array items become indexed keys such as items.0.name, so the path uniquely identifies every value.

Can I convert flattened keys back to nested JSON?

Yes — the unflatten mode reconstructs the original nested structure from dot-notation keys.

JSON Flatten / Unflatten

Flatten nested JSON to dot-notation keys and unflatten back.

Separator

JSON input

Flattened

{
  "user.name": "Alice",
  "user.address.city": "NYC",
  "user.address.zip": "10001",
  "user.tags.0": "admin",
  "user.tags.1": "user"
}

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About JSON Flatten / Unflatten

Flatten a nested JSON object into a single level of dot-notation keys (e.g. user.address.city), and unflatten it back. Handy for diffing configs, loading JSON into spreadsheets, or feeding flat key/value stores.

How to use

Paste your nested JSON into the input.
Choose flatten to expand nested keys into dot/bracket paths, or unflatten to rebuild the nested object.
Copy the result for use in env files, spreadsheets, or feature-flag systems.

Frequently asked questions

How are arrays handled?: Array items become indexed keys such as items.0.name, so the path uniquely identifies every value.
Can I convert flattened keys back to nested JSON?: Yes — the unflatten mode reconstructs the original nested structure from dot-notation keys.