What happens to arrays in the JSON?

Array elements are flattened using zero-based bracket index notation, for example items[0].name. This keeps array membership clear while staying flat.

Can I change the separator from a dot to something else?

Yes. Type any character or string in the Separator field before clicking Flatten. Common choices are underscore (_), double underscore (__), or forward slash (/).

Does the tool handle null and boolean values?

Yes. null, true, false, numbers, and strings are all preserved as-is in the flat output.

Is there a size limit on the JSON I can paste?

There is no hard limit — everything runs in your browser. Very large files (several MB) may be slow depending on your device.

Is my data sent to a server?

No. All processing happens entirely in your browser. Your JSON never leaves your device.

JSON Flattener

Name: JSON Flattener
Availability: InStock
Author: Nham Vu

Paste any nested JSON and instantly get a flat, single-level object using dot-notation keys.

Input JSON

Separator

Index arrays (e.g. items[0])

Flat Output

Paste JSON and click Flatten

Copied!

Summary

Paste any nested JSON and instantly get a flat, single-level object using dot-notation keys.

How it works

Paste or type your nested JSON into the input panel.
Choose an optional separator (default is a dot).
Click Flatten to produce the single-level output.
Review the flat key-value pairs in the output panel.
Click Copy Output to copy the result to your clipboard.

Use cases

Prepare API response data for import into a spreadsheet.
Debug deeply nested configuration objects.
Map JSON fields to flat database column names.
Simplify log payloads for search indexing.
Compare two flat objects for key differences.
Generate dot-path references for template engines.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu