JSON Formatter / Validator
Pretty-print, validate, and minify JSON instantly. Perfect for debugging API responses, config files, and data payloads. All processing in your browser.
Input JSON
Output
Why formatting and validating JSON matters
JSON is the lingua franca of APIs, cloud configs and infrastructure state. A single misplaced comma or unquoted key can break a deploy, and minified JSON returned by an API is nearly impossible to read by eye. Pretty-printing restores indentation and structure so you can scan nested objects quickly, while validation catches the syntax error before it reaches a pipeline or a running service.
Format, validate and minify in your browser
This tool parses your JSON locally and reformats it with consistent indentation, or minifies it to the smallest valid form. Nothing is sent to a server, which matters when the payload contains tokens, Terraform state fragments or customer data. Because it uses a real parser, an invalid document is rejected with the position of the problem, turning a vague deploy failure into a precise, fixable error.
Common JSON mistakes and how to fix them
Trailing commas, single quotes instead of double quotes and unquoted keys are the top three syntax errors, all of which strict JSON forbids. Another is confusing JSON with JavaScript objects or JSON5, which allow comments and trailing commas that standard parsers reject. When JSON drives infrastructure, keep it in version control and validate it in CI. For managing declarative infrastructure config safely, see our Terraform best practices guide.
Frequently asked questions
Why is my JSON invalid?
Most often a trailing comma, single quotes, or an unquoted key. Strict JSON requires double quotes and no trailing commas.
Can JSON have comments?
Standard JSON cannot. Comments are only allowed in JSON5 or JSONC, which many parsers do not accept.
Does formatting change my data?
No. Pretty-printing only changes whitespace and indentation; the values and structure stay identical.
What is minifying JSON?
Removing all optional whitespace to produce the smallest valid document, useful for reducing payload size.