Dev Tools

JSON Flatten / Unflatten

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

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

  1. Paste your nested JSON into the input.
  2. Choose flatten to expand nested keys into dot/bracket paths, or unflatten to rebuild the nested object.
  3. 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.