WHOIS Lookup

Look up domain registration information using the free RDAP protocol. Find registrar, creation and expiry dates, nameservers, and domain status. No API key required.

Enter a domain and click Look Up.

About WHOIS Lookup Tool

Look up domain registration information using the Registration Data Access Protocol (RDAP), the modern replacement for WHOIS. RDAP provides structured, machine-readable domain data with better security and standardization. All queries are made over HTTPS.

Domain Registration Info

Find out who registered a domain, when it was created, when it expires, and who the registrar is. Essential for domain research and verification.

Nameserver Lookup

Identify the authoritative nameservers for any domain. Useful for troubleshooting DNS configuration and understanding domain hosting setup.

Free RDAP Protocol

Uses the standardized RDAP protocol — no API key, no registration, no rate limits. Works with all major TLDs including .com, .org, .net, and more.

Structured Results

Domain data is displayed in a clean, organized table. Raw RDAP JSON is available for developers who need the detailed response.

📋 Common Use Cases

Pre-Commit Checking

Validate JSON, HTML, or other structured data before committing to your repository. Prevent broken configs from reaching production.

API Response Verification

Validate JSON responses from your API endpoints during development and testing. Ensure your data contracts are well-formed.

Configuration Debugging

Find syntax errors in JSON configuration files, package.json, or manifest files. Get line-level error details for quick fixes.

Code Quality Assurance

Validate HTML for accessibility and standards compliance. Catch missing tags, invalid attributes, and structural issues.

🪜 How to Use This Tool

  1. Paste code or data to validate
    Enter JSON, HTML, or other structured text into the input area. Syntax errors are highlighted in real time.
  2. Review error details
    See line numbers, column positions, and descriptions for each issue. Click errors to jump to the problematic location.
  3. Fix and revalidate
    Edit in place and see validation results update automatically. Iterate until your code is clean.
  4. Copy validated code
    Once valid, copy the code for use in your project. Some validators also format/beautify the output.

📚 Related Guides

Frequently Asked Questions

Are these dev tools free?▼
Yes. All dev tools are completely free. No signup, no account.
Is my data sent to a server?▼
No. Base64 encoding, URL encoding, JWT decoding, hash generation, and regex testing all happen in your browser. Your tokens and secrets stay on your device.
Can I decode JWTs safely?▼
Yes. JWT decoding happens entirely in your browser. The token never leaves your device. Only the header and payload are decoded — signatures are not verified server-side.