Syntax Validation Tools
JSON5 Validator
Validate JSON5 configuration text, including comments, single-quoted strings, unquoted keys, and trailing commas.
✓ Every tool runs in your browser. We do not upload your input or output.
Keyboard shortcuts
Ctrl/⌘ + Enter: process
Ctrl/⌘ + Shift + F: full screen
Esc: exit full screen
Ctrl/⌘ + F in editor: search
How to use
- Paste a JSON5 document into the editor.
- Run validation and read the line and column of any parsing error.
- Correct the nearby token or delimiter and validate again.
- Use JSON Validator instead when a consumer requires strict JSON.
Examples
Check a local configuration
An unquoted key and a trailing comma are allowed in JSON5 but not strict JSON.
{ retries: 3, debug: true, }Valid JSON5 syntax
Check the right configuration format
JSON5 is helpful in hand-edited configuration files because it allows comments and less punctuation than strict JSON. Paste a document to check that its delimiters, strings, and values form valid JSON5. The tool reports parser errors near their source location. It does not change the input or silently strip comments.
The distinction between JSON and JSON5 matters when data crosses an API boundary. A document with comments or a trailing comma may be valid here and rejected by a JSON-only service. Use the regular JSON Validator to check that stricter format. Syntax checks also do not know whether your application recognizes a particular setting; consult the application’s schema for semantic validation. This page runs entirely in your browser, and uploaded configuration text is not sent to a backend.
If you are converting a JSON5 document for another system, parse it first and then explicitly serialize it as strict JSON with an appropriate converter. Merely removing comments by hand can leave trailing commas or unquoted keys behind. Keep a copy of the original configuration.
Frequently asked questions
Is JSON5 the same as JSON?
No. JSON5 accepts extra syntax such as comments and trailing commas.
Will an API accept JSON5?
Only if that API explicitly supports JSON5. Most JSON endpoints expect strict JSON.
Does validity confirm the configuration meaning?
No. This tool checks syntax, not application-specific keys or values.
Can I use a multiline document?
Yes. Parsing errors include line and column details when available.