Email Validator
Validate emails with syntax checks, typo detection, disposable-domain detection, and role-based detection.
Free & unlimitedWorks offline
Email address
Checks run entirely in your browser. MX records can only be simulated for known providers — for production use, pair with a server-side verification API.
All processing happens in your browser. No data is sent to any server.
About this tool
- 1
Paste your email HTML
Enter the full HTML source code of your email template.
- 2
Run validation
Click validate to scan for compatibility issues across email clients.
- 3
Review issues
See a categorized list of warnings and errors with explanations for each.
- 4
Fix and re-validate
Address the flagged issues in your code and re-run to confirm fixes.
- Inline your CSS before validating - most email clients strip out <style> tags in the <head>.
- Avoid using shorthand CSS properties like "font" or "background" as they are inconsistently supported.
- Use table-based layouts for maximum compatibility with older email clients like Outlook.
- Always include alt text on images since many email clients block images by default.
- Checks HTML and CSS for email client compatibility issues
- Flags unsupported CSS properties per email client
- Detects missing alt text, broken structure, and accessibility issues
- Categorizes issues by severity: errors, warnings, and suggestions
- Links to documentation for each flagged issue
- Validate a new email template before deploying it to your email service provider
- Catch Outlook-specific rendering issues before they reach recipients
- Audit an existing email template library for compatibility problems
- Ensure transactional emails meet accessibility and deliverability standards
It checks against major clients including Gmail, Outlook (desktop and web), Apple Mail, Yahoo Mail, and popular mobile apps. Each issue specifies which clients are affected.
Many email clients strip <style> blocks from the <head>. Inlining CSS as style attributes on each element ensures your styles are preserved across all clients.
Validation catches known compatibility issues but cannot guarantee pixel-perfect rendering. Always send test emails to real clients for final verification.