What is a JSON formatter?

A JSON formatter (also called a JSON beautifier) takes minified or poorly formatted JSON and adds proper indentation and line breaks to make it human-readable. Formly's formatter also validates the JSON and shows syntax errors with line numbers.

What's the difference between format and minify?

Format adds whitespace and indentation for readability. Minify removes all whitespace to produce the smallest possible JSON string — useful for APIs and data transfer.

Does it show where JSON errors are?

Yes — when your JSON has syntax errors, the validator shows the exact error message from the JavaScript parser, which typically includes the line and character position of the error.

Is there a file size limit?

The formatter works with JSON of any size in the browser. For extremely large files (>10MB), performance may vary depending on your browser.

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JSON Formatter & Validator

Free to Use

Format, minify, and validate JSON instantly. See detailed stats, error messages with line numbers, and copy the result.

Paste JSON

Frequently Asked Questions

Is this JSON formatter free to use?›

Yes, completely free. No account, sign-up, or payment required — just paste your JSON and go.

What JSON standards does it support?›

It supports standard JSON (RFC 8259), including nested objects, arrays, strings, numbers, booleans, and null values. It does not support JSON5 or JSONC (comments) since those are not valid JSON.

How accurate is the validation?›

The validator uses the built-in browser JSON.parse engine, which is byte-perfect. If it reports an error, the input genuinely violates the JSON spec, and the error message includes the exact position of the problem.

What are common use cases?›

Developers use it to pretty-print API responses, minify JSON before committing to a repo, spot typos in config files, and quickly inspect deeply nested data structures using the depth and key stats.

Is my JSON data private?›

Yes. All processing happens entirely in your browser — your JSON is never uploaded to any server.

What Is JSON Formatter & Validator?

A JSON formatter prettifies minified JSON with proper indentation and line breaks, validates JSON for syntax errors, and minifies JSON for production use. Formly's free JSON formatter also highlights specific error locations when JSON is invalid, provides a collapsible tree view of nested objects, and supports JSON to CSV conversion for spreadsheet import.

Why Formly's JSON Formatter & Validator Is the Best Free Option

✓Validates JSON and highlights the exact line and character of syntax errors.
✓Prettify (format) and minify in one tool.
✓Collapsible tree view for navigating deeply nested JSON objects.
✓JSON to CSV conversion for spreadsheet import.
✓Free and processes data locally — JSON never sent to any server.

Free Alternative to JSONLint, JSON Formatter Chrome Extension, jsonformatter.org

→JSONLint: JSONLint validates but has limited formatting. Formly does both plus conversion.

→JSON Formatter Chrome Extension: Requires browser extension installation. Formly works in any browser without extensions.

→jsonformatter.org: Third-party website. Formly processes JSON in-browser without any data transmission.

Who Uses JSON Formatter & Validator?

Developers

Debug API responses and configuration files by formatting and validating JSON.

QA engineers

Inspect test data and API payloads for correctness.

Data analysts

Format and convert JSON data from APIs into CSV for analysis.

Popular searches: JSON formatter online, JSON validator, JSON beautifier, format JSON, JSON pretty print, JSON editor online, minify JSON.

Looking for a detailed guide? Read our in-depth tutorial on using JSON Formatter & Validator for professional results.

Read Guide →

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