JSON Formatter & Validator
Prettify, validate, format, and minify messy raw JSON strings. Instantly detects missing braces, invalid trailing commas, and formatting syntax errors.
Why Validate and Format JSON?
JavaScript Object Notation (JSON) is the universal lingua franca for REST APIs, GraphQL payloads, microservices, and web configuration files. When payloads are minified or generated dynamically, syntax flaws like unquoted strings or trailing commas can easily break client parsers.
- Immediate Syntax Error Localization: If your JSON payload is invalid, the validator pinpoints the exact character offset and cause (e.g. Unexpected token , in JSON at position 42).
- Configurable Indentation: Switch effortlessly between standard 2-space indentation (modern frontend standard) and 4-space indentation (backend preference).
- Payload Minification: Strip whitespace, tabs, and linebreaks to reduce API payload transit weight for maximum bandwidth efficiency.
- Confidential & Client-Side: API keys, session tokens, and sensitive JSON payloads remain securely isolated inside your browser.
Frequently Asked Questions
What causes common JSON parse errors?
The three most common JSON errors are: (1) using single quotes instead of double quotes around keys and strings, (2) trailing commas after the last item in arrays or objects, and (3) unescaped newline characters.
Are single quotes allowed in valid JSON?
No. RFC 8259 specifies that string literals and keys in JSON must be wrapped in double quotes ("), not single quotes (').