URL, Email & Domain Validator
RFC-compliant validation with TLD verification, disposable email detection, IDN/Punycode support, and batch processing.
How to Use
Validate URLs, email addresses, and domain names in one place. The tool auto-detects what you paste, runs RFC-compliant checks, and flags issues with clear explanations.
- Paste one or more entries into the input area, one per line. You can mix URLs, emails, and domains freely — the tool categorizes each line automatically.
- Review the results below the input. Each entry shows a Valid/Invalid badge and a type badge (Email, URL, Domain). Click any result to expand its full validation report.
- Use the stats bar for a quick summary of how many entries are valid, invalid, and what types were detected.
- Filter results by status (valid/invalid) or type (email/URL/domain) using the filter pills below the stats bar.
- Export results as CSV for batch processing, or copy the full text report to your clipboard.
About This Tool
URL and email validation is one of the most deceptively complex problems in web development. A simple regex is wrong more often than right — RFC 5322 allows quoted local parts, IP address literals, and internationalized domain names that break naive patterns. This tool implements proper validation logic for all three input types.
Email Validation (RFC 5322)
The email validator checks the local part character-by-character against the atext production from RFC 5322 section 3.2.3. Quoted local parts (e.g., "john doe"@example.com) are handled as a separate case. Domain validation checks label lengths (max 63 chars), total length (max 253), and TLD validity against the IANA root zone database. Additional checks flag disposable email providers, role-based addresses (admin@, support@), and sub-addressing (+ tags).
URL Validation
URLs are parsed using the browser's native URL API, which implements the WHATWG URL Standard. Beyond basic syntax, the tool checks protocol safety (HTTP vs HTTPS), embedded credentials, private IP ranges, non-standard ports (with service identification), double-encoding patterns, and URL length limits (IE/Edge 2083 character maximum). Internationalized Domain Names (IDN) are detected and their Punycode equivalents shown.
Domain Validation
Domain names are validated against DNS naming rules: each label must be 1-63 characters, start and end with alphanumeric characters, and the total length must not exceed 253 characters. The TLD is verified against the IANA root zone. Internationalized domain names are converted to Punycode for verification. The tool also identifies the registrable domain (eTLD+1) and any subdomains.
Internationalized Domains (IDN)
Internationalized Domain Names encode non-ASCII characters using Punycode (the xn-- prefix). For example, münchen.de becomes xn--mnchen-3ya.de in DNS. This tool converts between the two representations automatically and validates both forms.
Why Use This Tool
Input validation is a critical security boundary in every web application. Here are the most common use cases for this tool:
- Form validation testing — Test edge cases against your own form validators. Does your email regex correctly handle quoted local parts? Does it reject domains with numeric-only TLDs? Paste your test cases here to compare results.
- Data cleanup — Validate a CSV column of email addresses or URLs before importing into a CRM, mailing list, or database. The batch mode processes thousands of entries and exports results as CSV.
- Disposable email detection — Identify temporary/disposable email addresses (Mailinator, Guerrilla Mail, etc.) in your user registrations. The tool flags over 50 known disposable providers.
- Security auditing — Check URLs for embedded credentials, private IP addresses, double-encoding attacks, and suspicious TLDs. Useful during penetration testing or log analysis.
- DNS configuration — Validate domain names before configuring DNS records, SSL certificates, or email routing. The tool checks label lengths, TLD validity, and IDN encoding.
- API development — Verify that your API correctly validates input. Test with RFC edge cases like IP address literals in emails, IPv6 URLs, or Punycode domains.
Privacy
All validation runs entirely in your browser using JavaScript. No URLs, email addresses, or domains are sent to any server. No DNS lookups, no MX record checks, no network requests. Your data stays on your machine.