Flatten or Unflatten JSON
About JSON Flattener
This tool converts nested JSON objects into flat key-value pairs using dot notation (or other separators).
Flatten Mode: Takes nested objects like {"a":{"b":{"c":1}}} and converts them to {"a.b.c": 1}. Arrays are also flattened using numeric indices.
Unflatten Mode: Reverses the process, converting flat dot-notation keys back into nested objects.
Use Cases:
- Simplify complex nested API responses for easier processing
- Convert configuration files between flat and nested formats
- Prepare JSON data for spreadsheet import or database storage
- Debug deeply nested objects by viewing all paths at once
- Transform data between different system requirements
All processing happens in your browser. Your data is never sent to any server.
FAQ
What separators can I use?
You can choose between dot (.), slash (/), or underscore (_) as the separator character. Dot notation is most common and is the default.
How are arrays handled?
Arrays are flattened using numeric indices. For example, {"arr":[1,2,3]} becomes {"arr.0": 1, "arr.1": 2, "arr.2": 3}.
Can I unflatten any flat object?
Yes, as long as the keys follow the separator pattern. The tool will reconstruct the nested structure, creating objects for string keys and arrays for numeric keys.
What is the maximum depth supported?
There is no hard limit, but extremely deep nesting (100+ levels) may affect performance. The tool displays the maximum depth in the statistics.
What if my keys already contain the separator character?
If your JSON keys already contain the separator character, choose a different separator to avoid conflicts. For example, if you have keys with dots, use slash or underscore instead.
Privacy & Limitations
- All calculations run entirely in your browser -- nothing is sent to any server.
- Results are computed locally and should be verified for critical applications.
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JSON Flattener FAQ
What is JSON Flattener?
JSON Flattener is a free developer tools tool that helps you Flatten nested JSON objects into dot-notation key-value pairs.
How do I use JSON Flattener?
Enter your input values, review the calculated output, and adjust inputs until you reach the result you need. The result updates in your browser.
Is JSON Flattener private?
Yes. Calculations run locally in your browser. Inputs are not uploaded to a server by default, and refreshing the page clears session data.
Does JSON Flattener require an account or installation?
No. You can use this tool directly in your browser without sign-up or software installation.
How accurate are results from JSON Flattener?
This tool applies standard formulas or deterministic processing logic for estimates. For medical, legal, tax, or investment decisions, verify with a qualified professional.
Can I save or share outputs from JSON Flattener?
You can bookmark this page and copy outputs manually. Results are not persisted in your account and are typically not embedded in the URL.