Structured Data
Nested Data Flattener
Turn nested JSON into a flat list of paths such as user.address.city, or rebuild
nested JSON from flat paths. Copy the result or download it — your data never leaves the page.
Input
nested JSONPaste nested JSON to flatten, or a flat JSON object of paths to reconstruct. Your input is parsed in the browser and is never uploaded.
Output
readyHow it works
Flatten walks your JSON with the browser’s own JSON.parse() and records
each leaf as a path. Objects extend the path with a separator, arrays use their index, and
empty objects and arrays stay as {} and [] so nothing is lost.
Reconstruct splits each flat key back into segments and rebuilds the tree; a node whose keys
are the consecutive numbers 0, 1, 2… is turned into an array. Paths that
disagree with each other, such as a and a.b, are reported instead
of silently overwriting data. The optional share link keeps everything in the URL fragment,
which never leaves your browser.