Email HTML Validator
Validate HTML for email compatibility
HTML Content
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Try Now JWT CreatorWhat is Email HTML Validator?
An Email HTML Validator is a specialized tool that checks HTML code for compatibility with email clients and identifies potential rendering issues. Unlike web browsers, email clients have strict limitations on HTML and CSS support, making email development challenging. Our validator analyzes your HTML code against email client standards, checking for unsupported elements, CSS properties, and structural issues that could cause display problems. The tool provides detailed feedback on compatibility across major email clients including Gmail, Outlook, Apple Mail, and mobile email apps. It identifies deprecated elements, suggests table-based alternatives to div layouts, validates inline CSS usage, and recommends best practices for maximum deliverability. Whether you're creating newsletters, transactional emails, or marketing campaigns, this validator ensures your emails display consistently across all major email platforms.
When to Use Email HTML Validator
Use our Email HTML Validator whenever you're developing email templates, newsletters, or any HTML content intended for email distribution. This tool is essential before launching email marketing campaigns, sending important transactional emails, or deploying automated email sequences. Email marketers rely on it to ensure campaigns display correctly across all subscriber email clients, preventing broken layouts that could hurt engagement rates. Developers use it when building email templates for applications, testing responsive email designs, or troubleshooting client-specific rendering issues. It's particularly valuable when working with complex email designs, implementing new email features, or ensuring compliance with email accessibility standards. The tool is also crucial for agencies managing multiple client email campaigns and need to guarantee professional presentation across diverse email environments.
How to Use Email HTML Validator
7 stepsPaste your email HTML code into the validator input field
Click 'Validate Email HTML' to analyze your code for compatibility issues
Review the validation results showing supported and unsupported elements
Check the email client compatibility report for specific platforms
Address any warnings or errors highlighted by the validator
Implement suggested improvements for better email client support
Re-validate your updated code to ensure all issues are resolved
Privacy & Security
100% SecureYour email HTML code is processed entirely within your web browser using client-side JavaScript technology. No HTML content, email templates, or validation results are transmitted to our servers or stored anywhere outside your device. This ensures complete privacy and security for proprietary email designs, customer communications, and marketing materials. The tool works offline once loaded, providing an additional layer of security for confidential email template development.
Pro Tips
7 tipsAlways use table-based layouts instead of div-based designs for maximum email client compatibility
Keep CSS inline rather than using external stylesheets, as many email clients strip out <style> tags
Test your validated emails in actual email clients, not just the validator, for real-world verification
Use web-safe fonts and always include fallback font families for consistent typography
Keep email width under 600px for optimal display across desktop and mobile email clients
Validate images are properly sized and include alt text for accessibility and deliverability
Regular validation during development prevents major compatibility issues at launch time
Frequently Asked Questions
5 Q&AQ1:Why do emails look different in different email clients?
Email clients use different rendering engines and support varying levels of HTML and CSS. Unlike web browsers, email clients often strip out advanced CSS, have limited JavaScript support, and handle responsive design differently. This validator helps identify compatibility issues before sending.
Q2:What HTML elements should I avoid in emails?
Avoid using div-based layouts (use tables instead), CSS Grid, Flexbox in older clients, JavaScript, external stylesheets, and advanced CSS selectors. Stick to inline CSS, table-based layouts, and widely supported HTML elements for maximum compatibility.
Q3:How can I make my emails mobile-friendly?
Use responsive design with media queries, scalable images, readable font sizes (14px+), touch-friendly buttons (44px minimum), and single-column layouts for narrow screens. Test across various mobile email apps as they have different rendering capabilities.
Q4:What's the difference between web HTML and email HTML?
Email HTML is much more restrictive than web HTML. Email clients don't support many modern web standards, require table-based layouts for reliability, need inline CSS for styling, and have limited support for interactive elements. Email HTML follows older web standards for broader compatibility.
Q5:Which email clients should I prioritize for testing?
Focus on Gmail, Outlook (desktop and web), Apple Mail, Yahoo Mail, and mobile clients like iOS Mail and Android Gmail. These cover the majority of email users. Each has unique rendering quirks that this validator helps identify.
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