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Validate JSON Online
Validate JSON syntax with helpful error messages. Use JSON Validator in your browser with no signup, no daily limit, and no backend processing for tool input.
Problem
You need to check whether data is valid before it breaks an import, API request, config file, or review workflow.
What to do
Validation catches structural mistakes early. Use it before committing config, sending API payloads, importing files, or sharing samples with a teammate.
- 1Paste or upload the data into JSON Validator.
- 2Review the first reported error or warning.
- 3Fix the source and validate again until it passes.
Use the browser tool
JSON Validator checks JSON syntax and reports the exact line and reason for any error in plain English, so you can fix malformed payloads fast. It runs as you type, entirely in your browser, making it safe for private or production data.
People also ask
- How do I use JSON Validator?
- Paste or drop your data into the workspace, adjust the options to fit your data, then copy or download the result. Validate JSON syntax with helpful error messages.
- Is my data uploaded or stored anywhere?
- No. Everything runs locally in your browser — your data is never uploaded to a server. Nothing is sent to a server, so it's safe to use with private or sensitive data.
- Is JSON Validator free?
- Yes — it's completely free with no account, no sign-up, no watermark, and no daily usage limits.