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JSON Formatter & Validator

Format, minify, validate, and convert JSON — free, no signup required.

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JSON Full Form

JSON stands for JavaScript Object Notation. It is a lightweight, text-based, language-independent data interchange format derived from JavaScript, used to transmit structured data between servers and web applications.

JSON supports primitive types (strings, numbers, booleans, null) and structured types (objects and arrays). It is widely used in REST APIs, configuration files, and data storage due to its simplicity and readability.

What this tool does

  • Format / Beautify — Indent JSON with 2, 3, 4 spaces or tabs for readability.
  • Minify / Compact — Strip whitespace to reduce payload size.
  • Validate — Check syntax and pinpoint the offending line on error.
  • Convert — Transform JSON to XML, CSV, TSV, YAML, or plain text.
  • Tree View — Explore JSON as a collapsible tree.
  • Upload / Load URL / Download — Bring data in from a file or URL and save results locally.

When you need a JSON formatter

  • API development — Inspect the response body of a REST or GraphQL endpoint in a human-readable form.
  • Debugging — Track down a syntax error (missing comma, extra bracket, trailing comma) that a parser rejected.
  • Data exploration — Browse a large nested payload using tree view instead of scrolling raw text.
  • Reducing payload size — Minify JSON before embedding it in a page, a URL, or a bundle.
  • Data conversion — Export JSON to CSV for a spreadsheet, or to YAML for a config file.
  • JMESPath transforms — Filter, sort, or project a slice of a large JSON document without writing code.

Privacy

Everything runs locally in your browser. Your JSON, uploaded files, and URL responses are never sent to our servers. You can use this tool on sensitive data without it leaving your machine.

Frequently Asked Questions

No. All formatting, validation, and conversion happens entirely in your browser using JavaScript. Your data never leaves your machine, so you can safely paste sensitive payloads (API responses, tokens, config files) without worrying about logging or third-party access. The only exception is the "Load URL" feature, which fetches the URL you explicitly provide — and that request is subject to the remote server's CORS policy.
Formatting (also called beautifying or pretty-printing) adds indentation and line breaks to make JSON easy to read — useful during development and debugging. Minifying strips all unnecessary whitespace to produce the smallest possible string — useful when you want to reduce network payload size, embed JSON in a URL, or ship it in a bundle. Both operations preserve the exact semantic content of the data.
The most common JSON errors are: single quotes instead of double quotes around keys and string values, trailing commas after the last element of an object or array, unquoted keys, JavaScript comments (// or /* */), or undefined/NaN/Infinity values which are not valid JSON. Click Validate and the tool will report the exact line and column of the offending token so you can fix it quickly.
Paste your JSON into the input pane, then click the Convert JSON to dropdown in the center action bar and pick your target format — XML, CSV, TSV, YAML, or plain text. The result appears in the output pane, which you can copy or download. For CSV/TSV, the tool expects an array of flat objects with consistent keys for best results.
JMESPath is a query language for JSON — think of it as "XPath for JSON" or "jq in the browser". Use the Transform button to filter a slice out of a large document (e.g., users[?active==`true`].email), sort items, pluck fields, or project a reshaped structure. It's the fastest way to explore deeply nested data without writing code. Visit jmespath.org for the interactive tutorial.
There is no hard limit imposed by the tool, but browser performance will degrade with very large payloads (several MB or more) because all work happens in the main thread. For most real-world API responses — up to a few hundred thousand lines — the tool stays responsive. For multi-megabyte dumps, consider a command-line tool like jq instead.