JSON Syntax validator
Check whether pasted JSON is syntactically valid and locate parsing errors.
How to use the JSON Syntax validator
What does the JSON Syntax validator do?
Check whether pasted JSON is syntactically valid and locate parsing errors; It applies this page-specific rule: check whether pasted JSON is syntactically valid and locate parsing errors.
Which inputs does this validator use?
To check whether pasted json is syntactically valid and locate parsing errors, enter Input, Result; keep every value in the same example; select Check input when the values are ready; Start with a familiar case covered by this rule - The validator parses the complete value and reports the position of malformed JSON syntax - so the expected result can confirm the settings.
How should the validator result be read?
For a result intended to check whether pasted json is syntactically valid and locate parsing errors, the validator parses the complete value and reports the position of malformed JSON syntax; read result together with the original input rather than as an isolated answer, and confirm that its units or structure match the intended use.
What errors can it find?
When the goal is to check whether pasted json is syntactically valid and locate parsing errors, it detects problems such as unquoted keys, trailing commas, missing delimiters, and unmatched braces.
Does valid JSON guarantee a valid API request?
When using the page to check whether pasted json is syntactically valid and locate parsing errors, no.
Limits and accuracy
When using this validator to check whether pasted json is syntactically valid and locate parsing errors, a syntax pass confirms valid JSON structure, not that required application fields or value ranges are present; a passing result confirms the rules tested on this page, but it does not prove that an address, identifier, account, or remote resource exists; keep input until the output has been checked in its intended destination.
What JSON Syntax validator does
Check whether pasted JSON is syntactically valid and locate parsing errors.
Enter the value or list you want to check in the labeled controls. The JSON Syntax validator result stays separate so you can review it before copying, downloading, or using it elsewhere.
Your work is processed in this browser tab. Keep the original whenever a conversion changes formatting, dimensions, or precision.
Frequently asked questions
Does the validator accept JSON with comments?
This implementation parse the text with the browser's JSON parser, report the first syntax error with line and column, and optionally pretty-print valid input. The output is validity status, error location and message, or normalized pretty-printed JSON.
How are line and column numbers calculated?
The tool handles only the format and rules described on this page. It validates JSON grammar itself rather than evaluating a JSON document against a schema. It does not contact a remote validation or lookup service.
Is pasted JSON processed entirely in my browser?
Input is processed by JavaScript in the current browser tab. Nothing entered in the tool is sent to Plain Tools; keep the original when the transformation is lossy.