About this tool
Validate JSON syntax and get clear error messages. Useful when reviewing API responses, cleaning config before commit, or sharing readable snippets in docs and PRs.
Paste the JSON document you want to check into Input. Click Validate. Example — Confirm a webhook payload parses: try `{"event":"invoice.paid","amount_cents":4999,"currency":"usd"}` and expect something like `Valid JSON`.
This checks syntax only — not business rules, required fields, or types. See also: JSON Formatter, and JSON Schema Validator. Runs in your browser — nothing you paste gets uploaded.
How to use
- Paste the JSON document you want to check into Input.
- Click Validate.
- On success, Output shows “Valid JSON”; on failure, read the error and adjust the input.
- Re-run Validate after each fix until it passes.
Example
Confirm a webhook payload parses
Input
{"event":"invoice.paid","amount_cents":4999,"currency":"usd"}Output
Valid JSON
Limitations
- This checks syntax only — not business rules, required fields, or types.
- Light repair may accept input that strict parsers elsewhere reject; verify with your runtime when in doubt.
- It does not compare against OpenAPI or JSON Schema definitions.
Related guides
1Related tools
2Frequently asked questions
What does the JSON Validator do?
Validate JSON syntax and get clear error messages. Runs in your browser — no install, no account.
How do I use the JSON Validator?
Paste the JSON document you want to check into Input. Click Validate. On success, Output shows “Valid JSON”; on failure, read the error and adjust the input. Re-run Validate after each fix until it passes.
Is the JSON Validator free?
Yes. No signup, no usage limits, no paywall.
Does the JSON Validator upload my data?
No. Processing happens locally in JavaScript. Your input is not uploaded, stored, or logged.
What are the limitations of the JSON Validator?
This checks syntax only — not business rules, required fields, or types. Light repair may accept input that strict parsers elsewhere reject; verify with your runtime when in doubt. It does not compare against OpenAPI or JSON Schema definitions.