Error guides

Step-by-step guides for common validation errors. JSON Tools hub →

• JSON unexpected token
• HTML unclosed tag
• Schema.org invalid type
• UUID invalid format
• Webhook payload invalid JSON
• robots.txt Allow/Disallow

FAQ

What can I validate with these tools?

You can validate JSON, HTML, CSV, XML, YAML, API responses, SOAP, webhooks, regex, config files, .env, logs, Base64, checksums, hashes, dates, timestamps, UUIDs, and more. All 33 tools are listed on the Browse Tools page and available via API.

Is there an API? Can AI agents use it?

Yes. GET /api/v1/status returns all endpoints and capabilities. Each validator has a POST endpoint (e.g. /api/v1/validate/json). Rate limit: 1 request per 10 seconds per IP without a key. The site is designed for both humans and AI: see /developers and /llms.txt for documentation and usage policy.

Do I need to sign up?

No. All tools are free to use in the browser without an account. API access is rate-limited without a key; no signup required for basic use.

How do I fix a validation error?

Each tool shows line and column when possible. We also have error guides: from a tool page or search, open a specific error (e.g. JSON trailing comma). Use «Try in validator» to prefill the broken example and fix it.

Are short URLs supported?

Yes. /json, /csv, /regex, /xml, /yaml, /html, /base64, and /robots redirect to the full tool pages for easy sharing.