Developer🔒 Runs in your browser

JSON Formatter

Beautify, minify & validate JSON data instantly

Input

Output

Formatted output appears here...

Use cases

Pretty-print a one-line API response copied from the browser dev tools.
Validate a JSON config file before committing it to a repo.
Minify a JSON payload before pasting it into a size-constrained field.
Sort keys alphabetically to compare two JSON files in a meaningful diff.
Find a parse error that broke a deployment by getting the exact line/column.

About JSON Formatter

JSON Formatter parses, validates and pretty-prints JSON entirely in your browser. Paste any JSON blob and the tool reformats it with consistent indentation, sorts keys if you want, and surfaces parse errors with the exact line and column. It also offers a minify mode that strips all whitespace for production payloads. Common scenarios: cleaning up a one-line API response copied from a network tab, validating a JSON config before committing, comparing two JSON shapes before deserializing, or compressing a payload before pasting into a size-limited field. Sensitive payloads (tokens, PII) stay on your machine — no network request is ever made.

Frequently Asked Questions

How do I format JSON data?

Paste your JSON into the editor and click the format button to beautify it with proper indentation, or click minify to compress it into a single line. The tool also validates your JSON and highlights any syntax errors.

Is my JSON data stored or sent anywhere?

No, all formatting and validation happens in your browser. Your JSON data is never transmitted to any server. This is safe for working with sensitive API responses, configuration files, or any private data.

Can the tool validate my JSON for errors?

Yes, the tool automatically validates your JSON and highlights syntax errors with helpful error messages indicating what went wrong and where. This makes it easy to quickly find and fix issues like missing commas, mismatched brackets, or invalid values.

Does the formatter modify the data, only the layout?

Only the layout — the parsed value is identical before and after. Property order may change if you enable sort-keys (since JSON object key order is not semantically significant, but text diffs become much cleaner). Numeric precision and string content are preserved exactly.

Can it handle very large JSON files?

Yes for tens of MB, since parsing happens with the native `JSON.parse`. The browser may slow down past ~50 MB because the formatted text needs to render in the textarea. For multi-hundred-MB files, prefer a CLI tool like `jq` to avoid hanging the page.

Use cases

Pretty-print a one-line API response copied from the browser dev tools.

Validate a JSON config file before committing it to a repo.

Minify a JSON payload before pasting it into a size-constrained field.

Sort keys alphabetically to compare two JSON files in a meaningful diff.

Find a parse error that broke a deployment by getting the exact line/column.