Data Converters

JSON Unflattener

Reverse JSON flattening, take an object with dot-path keys and restore it to its original nested structure. Useful when working with flattened database records or log entries.

Runs entirely in your browser No account needed Copy or download result
JSON (flat) JSON (nested)
Paste JSON (flat) below, or drop a file

Converted entirely in your browser; your data never leaves your device

Input Text Output JSON Browser-only No upload by default

Features

  • Restores nested objects from dot-path keys
  • Handles numeric indices as array positions
  • Supports dot, underscore, and slash separators
  • Download as .json file
  • Browser-only

How to use it

  1. Paste your flat dot-path JSON into the input.
  2. Select the separator used in the keys (dot is default).
  3. Nested JSON appears in the output.
  4. Copy or download.

Use cases

  • Restoring nested config from flattened environment variables
  • Reconstructing API payloads from flat database columns
  • Processing log entries that were stored flat

Limitations

  • Numeric path segments become array positions when they follow an array-like path.
  • Very large files depend on browser memory and device performance.
  • Malformed or highly specialized data may need manual cleanup before or after conversion.
See also

Related tools

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Questions & answers

Frequently asked

What if keys have both dot-path and regular keys?

Dot-path keys are expanded into nested objects. Regular keys (without the separator) remain at the top level.

Does JSON Unflattener upload my data?

Your file or text is processed in your browser and is not uploaded.

What does JSON Unflattener output?

It outputs nested JSON. Numeric path segments become array positions when they follow an array-like path.

Should I review the result before using it?

Yes. Data formats vary, so always review generated output before using it in production, database, or publishing workflows.