JSON Formatter & Validator
Format, validate, and minify JSON data instantly.
What Is a JSON Formatter and Why Do I Need One?
A JSON formatter takes raw or minified JSON data and reformats it with proper indentation and line breaks, making it easy to read and debug. It also validates the JSON syntax, highlighting errors if the data is malformed. Developers use this tool daily when working with APIs, configuration files, and data interchange.
How Do I Format and Validate JSON Online?
Paste your JSON into the text area above and click Format. The tool parses the JSON, validates its structure, and outputs a beautifully indented version. If there are syntax errors, it highlights the issue so you can fix it. You can also minify valid JSON to a single line for compact storage or transmission.
What Common JSON Errors Does This Tool Detect?
The tool catches missing or extra commas, unquoted keys, trailing commas (not valid in strict JSON), mismatched brackets and braces, single quotes instead of double quotes, and invalid escape sequences. The error message includes the position where the issue was found, helping you locate and fix problems quickly.
Is This Tool Safe for Sensitive API Data?
Yes. The formatter runs entirely in your browser using JavaScript's built-in JSON.parse and JSON.stringify methods. Your data never leaves your device, making it safe for API keys, authentication tokens, database records, and any other sensitive information.
What Is the Difference Between JSON and JavaScript Objects?
JSON (JavaScript Object Notation) is a strict data interchange format. Unlike JavaScript objects, JSON requires double-quoted keys and string values, does not allow trailing commas, comments, or undefined values, and cannot contain functions. Valid JSON is always valid JavaScript, but not all JavaScript objects are valid JSON. This tool validates against the strict JSON specification.
How Do I Pretty-Print JSON with Custom Indentation?
The formatter uses 2-space indentation by default, which is the most common convention. The formatted output is easy to read while remaining compact. For deeply nested structures, the consistent indentation makes it easy to visually trace the hierarchy. Copy the formatted output and paste it into your code editor, documentation, or API testing tool.