JSON Formatter and Validator
This tool turns compact or difficult-to-read JSON into an indented document and reports syntax errors before you copy it into another system.
Format and validate JSON in your browser
Paste a JSON object or array, then format it or validate its syntax.
Processing mode: browser-only for this tool. The interface does not require a server upload to perform its transformation.
Start with a focused browser tool
This tool turns compact or difficult-to-read JSON into an indented document and reports syntax errors before you copy it into another system.
Designed for: Developers, QA testers, and technical writers working with API responses.
How to use this tool
Paste a complete JSON object or array into the editor. Format produces readable indentation. Validate checks syntax without changing the input. The result panel identifies the browser error message when parsing fails.
How the result is produced
The browser JavaScript JSON.parse method checks syntax, and JSON.stringify serializes the parsed value with two-space indentation. This means the output is a parsed JSON value, not a best-effort text reformat.
Test examples
Input: {"name":"Ada","roles":["admin","editor"]}. Expected formatted output: an indented object with a roles array.\nInvalid input: {"name":"Ada",}. Expected result: a validation error because the trailing comma is not valid JSON.
Limitations
Comments are not part of standard JSON and will be rejected. The tool does not repair malformed data, infer missing quotes, or send the pasted text to a server. Very large documents may be limited by the available browser memory.
Privacy and processing
The transformation uses the browser JSON API. This plugin does not submit the editor contents to a WordPress endpoint for formatting.
Related guide
How to validate JSON before using an API response
Documentation
- https://www.json.org/json-en.html
- https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse
- https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify
This page describes the implementation shipped with the NOFYI Tool Factory. Review the interface output before using it in a production workflow.