How it works
The JSON Prettifier reformats minified, compressed, or inconsistently indented JSON into clean, human-readable text with proper indentation, line breaks, and consistent spacing — without changing the underlying data.
Minified JSON (a single unbroken line with no whitespace) is efficient for APIs and storage but nearly impossible for a human to read or debug. The Prettifier parses the JSON structure and re-serializes it with your chosen indentation (2 spaces, 4 spaces, or tabs), so nested objects and arrays are visually structured and easy to scan.
How to use it: paste any valid JSON — an API response, a config file, a log entry — into the input box. The formatted result appears instantly in the output panel with syntax highlighting for keys, strings, numbers, booleans, and null values, making it easy to spot the field you're looking for. If the input contains a syntax error (a missing comma, an unclosed brace), the tool reports the line and character position of the problem instead of silently failing.
Common uses: pretty-printing an API response copied from browser dev tools, formatting a ".json" config file before committing it, cleaning up JSON pasted from Slack or email that lost its formatting, and visually comparing two JSON payloads.
Privacy: parsing and formatting happen entirely client-side using the browser's native JSON parser. Nothing you paste — including API keys, tokens, or internal data structures that might appear in a payload — is ever transmitted to a server.
Frequently Asked Questions
- APIs and data files often use minified JSON (no spaces or newlines) to reduce file size. While machines read it fine, humans cannot scan the structure. Prettification adds indentation and line breaks to make nesting, keys, and values immediately visible.
- The tool shows a detailed error message indicating the line and column of the problem — for example, 'Unexpected token ; at line 3, column 12'. This helps you quickly locate and fix the syntax error.
- Two spaces is the most compact readable format and is the default in most JavaScript style guides (Airbnb, Google). Four spaces is the default in Python and many other languages. Choose based on your codebase convention.
- No. JSON objects are unordered by specification — the key order in a JSON object has no semantic meaning. Alphabetical key sorting produces semantically identical JSON that is easier to diff and read.
- Yes. If the input fails to parse, the error message tells you exactly where the issue is. Successfully prettified output is by definition valid JSON.