Web Tools
JSON Flatten/Unflatten
Flatten nested JSON objects to dot-notation key-value pairs and unflatten them back. Configure separator, array notation, and max depth. Runs entirely in your browser — your data never leaves your machine.
json flatten unflatten converter data dot-notation
Published May 29, 2026
All interactive tools run entirely in your browser. Your data never leaves your device.
How It Works
Paste nested JSON and instantly flatten it to a single-level object with dot-notation keys. Switch to unflatten mode to reconstruct nested structures from flat key-value pairs. Useful for working with flat configs, database queries, and data transformations.
Features
- Bidirectional: flatten nested JSON or unflatten dot-notation keys
- Custom separator: use
.(default),/,_, or any character - Array notation: dot (
items.0) or bracket (items[0]) style - Deep nesting: handles arbitrarily nested objects and arrays
- Empty handling: preserves empty objects
{}and arrays[] - Roundtrip: flatten then unflatten restores the original structure
- Key count: shows total number of keys in the output
- 5 examples: simple, arrays, deep nesting, API response, config
- Private: runs entirely in the browser — no data transmitted
Use Cases
- Converting nested configs to flat environment variable format
- Preparing data for flat key-value stores or spreadsheets
- Debugging deeply nested API responses by flattening them
- Transforming data between nested and tabular formats
- Working with NoSQL databases that prefer flat document structures