JSON Formatter & Validator
Beautify, validate and minify JSON online with the exact error line and column.
100% private: everything runs in your browser and nothing is uploaded.
How to Use the JSON Formatter
No sign-up, no installation — it works right here in your browser.
- Step 1:Paste your JSON into the input box, upload a .json file or click Load sample.
- Step 2:Choose the indentation and, optionally, sort keys alphabetically. The input is validated automatically while you type.
- Step 3:Click Format / Beautify or Minify, then copy the result or download it as a .json file. If the JSON is invalid, click Go to error to jump straight to the problem.
JSON Formatter FAQ
How do I format JSON online?
Paste your JSON into the input box and click Format / Beautify. The tool validates it, applies the indentation you choose (2 spaces, 4 spaces or tabs) and shows the pretty-printed result, ready to copy or download.
How does the JSON validator find errors?
If the JSON cannot be parsed, the validator reports the exact line and column of the first problem, explains the cause — for example a trailing comma, a missing quote or single quotes — and lets you jump straight to it.
Is my JSON data safe?
Yes. Formatting and validation run entirely in your browser. Your JSON is never uploaded to a server, so it is safe to use with API responses, configuration files and production data.
What is the difference between formatting and minifying JSON?
Formatting (beautifying) adds line breaks and indentation so JSON is easy to read and review. Minifying removes all unnecessary whitespace to make the payload as small as possible for storage or network transfer.
Why is my JSON invalid?
The most common causes are trailing commas, single-quoted strings, unquoted property names, comments and missing brackets. Standard JSON allows none of these, even though JavaScript does.
What Is a JSON Formatter and Validator?
JSON (JavaScript Object Notation) is the standard format for APIs, configuration files and data exchange, but it is often delivered as one dense line that is almost impossible to read. A JSON formatter, also called a JSON beautifier or pretty printer, parses that text and rewrites it with consistent indentation and line breaks so you can understand the structure at a glance. Our free online JSON formatter goes further: it validates the input as you type, counts keys and nesting depth, sorts keys alphabetically when you need a stable, diff-friendly order, and minifies the same data back to a single line in one click.
When JSON is invalid, a generic “Unexpected token” message rarely helps. This validator pinpoints the exact line and column of the first syntax error, explains the cause in plain language — trailing commas, single quotes, unquoted keys, missing brackets or invalid escape sequences — and shows the offending line with a caret. Everything runs locally in your browser, so you can safely format API responses, webhook payloads, package.json files and production logs without uploading a single byte. Files of up to 10 MB are supported.