Skip to tool

JSON Unflattener

Turn flat JSON back into nested objects.

Output will appear here…

How to Use This Tool

  1. Paste flat JSON.
  2. Set delimiter.
  3. Click Unflatten JSON.

Learn More About JSON Unflattener

When to unflatten JSON

Unflattening is useful when you need to restore original data structures after exporting or normalizing JSON.

About JSON Unflattener

Unflattening reconstructs nested structures from flat JSON. It's the perfect companion to a JSON flattener when you need to restore original data shapes.
Restore nested JSON from flat keys.
Runs in browser
Yes
Delimiter
Configurable
Array support
Yes

Examples

Unflatten a user object

Rebuild nested keys into an object tree.
Input
{
  "user.name": "Ava"
}
Output
{
  "user": {
    "name": "Ava"
  }
}

Features

Delimiter support

Match dot, slash, or custom delimiters.

Array reconstruction

Numeric keys become array indexes automatically.

Quick restore

Convert flat exports back to nested JSON.

Use Cases

  • Restore CSV-exported JSON to nested structure.
  • Rebuild analytics payloads after flattening.
  • Convert flat config keys into object trees.

Frequently Asked Questions

Related Tools

Flatten JSON first, then restore it when needed.