JSON5 Validator: Validate and Convert JSON5 to JSON
The JSON5 Validator checks whether pasted or dropped content follows JSON5 syntax, including unquoted keys, single-quoted strings, trailing commas, and comments. When the input is valid, you can convert it with one click to strict RFC 8259 JSON. If validation fails, the tool reports an error position to help you locate the syntax issue.
The JSON5 Validator checks JSON5 syntax and converts valid input to strict JSON. JSON5 is a superset of JSON that allows unquoted keys, single-quoted strings, trailing commas, and comments. Paste or drop content into the tool to check whether it is valid, then use the one-click conversion when you need RFC 8259 JSON.
When validation finds a syntax issue, the tool reports an error position to help you locate it. After correcting the input, run the check again to confirm it is valid. If validation succeeds, the conversion produces strict JSON; JSON5-only syntax, such as comments and trailing commas, cannot appear in strict JSON output.
JSON5 can be convenient for people editing data because it allows syntax such as comments and unquoted keys. Strict JSON follows tighter syntax rules, so converting JSON5 is useful when a parser or workflow expects RFC 8259 JSON. The validator helps you check the source before conversion and gives you a way to produce the stricter format from valid input.
The tool runs entirely in your browser, so your input is processed on your own device and is not uploaded, stored, or sent to a server. Once the page has loaded, it works offline because it has no server dependency. This makes it useful for developers and DevOps engineers who need to validate or convert JSON5 while keeping their data on their device.
Step 1: Paste your JSON5 content into the tool, or drop it in. Include the complete content you want to check.
Step 2: Run the validation check. The tool checks whether the input follows JSON5 syntax.
Step 3: Review the result. If the input is invalid, use the reported error position to help find the syntax issue.
Step 4: Correct the JSON5 input and run the check again if needed. This helps confirm the content is valid before you use it elsewhere.
Step 5: Convert valid JSON5 to strict JSON with the one-click conversion. The result follows RFC 8259 JSON syntax.
Use case: Check a JSON5 file before passing it to a parser, so you can catch syntax issues before they cause a runtime failure.
Use case: Find the reported error position when a large or unfamiliar file fails validation, rather than searching through it by hand.
Use case: Verify output from another tool by checking that it is valid JSON5, not just content that looks plausible.
Use case: Convert a JSON5 configuration that uses comments or trailing commas into strict JSON for a parser that expects RFC 8259 syntax.
Use case: Validate a configuration with unquoted keys or single-quoted strings before sharing it with teammates or using it in a project.
Use case: Turn valid JSON5 into strict JSON when a downstream workflow accepts JSON but not JSON5-specific syntax.