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JSON Formatter & Validator – Format, Validate & Minify | Tooltastic
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JSON Formatter & Validator

Format, validate and sort JSON instantly in your browser

Real-time formatting 100% local in browser Instant validation
Indent
JSON Input bytes
Formatted Output bytes
Input:
Output:
Saved:

Instant JSON formatting

Paste raw, minified, or broken JSON and get a clean, indented version in milliseconds. Supports 2 spaces, 4 spaces, or tab indentation.

Built-in syntax validator

Every keystroke is validated against the JSON spec. Syntax errors are highlighted immediately so you can fix them without guessing.

No data leaves your browser

All processing happens client-side in JavaScript. Your JSON is never sent to a server — perfect for sensitive API payloads and credentials.

Frequently asked questions about JSON formatting

Everything about pretty-printing, validation and best practices

Unformatted JSON is a single, often very long line that is almost impossible to read or debug. Formatted JSON adds indentation and line breaks so nested objects, arrays and key-value pairs become instantly visible. This saves time when reviewing API responses, config files or log data.

Two spaces are the de-facto standard in JavaScript projects and most style guides (Prettier, ESLint). Four spaces are common in Python (PEP 8) and Java ecosystems. Tab indentation keeps files compact and lets each developer set their preferred tab width in their editor. Pick the convention that matches your project's existing code style.

Sort keys reorders every object's properties alphabetically before formatting. This makes large JSON documents easier to scan because you can predict where a key appears. It also produces stable output: two JSON objects with the same data but different key orders will format to identical text, which is useful for diffing and version control.

Use Minify when you need the smallest possible payload for production: API responses, inline config, or JSON embedded in HTML. Minification strips all spaces and newlines, often reducing file size by 20–50 %. For development and debugging always use formatted JSON; only switch to minified output for the final build or deploy step.