Flatten nested JSON to dot notation

Convert nested JSON into a single-level object whose keys contain the original paths.

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ToolJSON Flatten
Input
Output
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How it works

Nested objects and arrays are traversed depth-first and each leaf is emitted under a delimiter-joined path such as user.name or items.0.id. Empty containers can remain as leaf values so their presence is retained.

  • Dot notation is the familiar path default.
  • Empty containers remain distinguishable from absent paths.

Worked example

Nested Object
Flatten a nested object into dot-notation keys
Input
											{"user":{"name":"Alice","address":{"city":"Portland","zip":"97201"}},"active":true}
Output
												{
  "user.name": "Alice",
  "user.address.city": "Portland",
  "user.address.zip": "97201",
  "active": true
}

When to use this

Spreadsheet exports, search indexes, and flat logging fields use path flattening.

Edge cases

  • A key containing the delimiter becomes ambiguous without escaping.
  • An empty object remains when retention is enabled.
  • Array indexes become path segments, so reordering changes flattened keys.

References