JSON Validator & Formatter – Beautify JSON Online
Free JSON validator and beautifier. Format, validate and pretty-print JSON instantly, find syntax errors and make API responses easy to read.
JSON validator & beautifier – Free Online Tool
Our free JSON Validator & Beautifier checks your JSON for errors and formats it with clean indentation. Paste messy or minified JSON and get readable, validated output instantly.
What is JSON validator & beautifier?
JSON (JavaScript Object Notation) is the most common format for APIs, configuration files and data exchange. It is strict: a single missing comma, extra trailing comma or unquoted key makes the whole document invalid.
A validator finds those mistakes, and a beautifier adds indentation and line breaks so humans can read nested data easily.
How to use the JSON validator & beautifier
- Paste your JSON.
- Click validate / beautify.
- Fix any errors reported.
- Copy the formatted JSON.
Key features
- Detects JSON syntax errors
- Pretty-prints with indentation
- Handles large and nested JSON
- Free and browser-based
Common use cases
- Reading API responses during development
- Fixing broken configuration files
- Formatting JSON for documentation
- Validating structured data such as JSON-LD schema
Frequently asked questions
Why is my JSON invalid?
Common causes are trailing commas, single quotes instead of double quotes and unquoted keys.
Can comments be used in JSON?
Standard JSON does not allow comments.
Is my data safe?
Avoid pasting secrets or personal data into any online tool.
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