Definition
Web fonts are typefaces that are not pre-installed on a user's device but are downloaded from a web server when the email is opened. In email, web fonts enable brands to use their custom typefaces for consistent typography across campaigns, rather than being limited to system fonts like Arial, Helvetica, or Georgia.
Web font support varies significantly across email clients. Apple Mail, iOS Mail, and Samsung Mail support web fonts well. Gmail (web and mobile) does not support web fonts and falls back to system fonts. Outlook desktop uses Word's rendering engine, which has limited web font support. Always provide a comprehensive font stack with fallbacks.
Web Font Support by Client
| Email Client | Web Font Support |
|---|---|
| Apple Mail (iOS/macOS) | Full support |
| Samsung Mail | Full support |
| Gmail (web) | Not supported |
| Gmail (mobile) | Not supported |
| Outlook desktop | Limited |
| Outlook.com | Supported |
| Yahoo Mail | Supported |
Best Practices
- Always provide fallback fonts in your font stack for clients that do not support web fonts
- Use widely supported web font formats (WOFF, WOFF2)
- Host web fonts on a fast CDN to minimise load time delays
- Limit the number of web font families to 1–2 for performance
- Use web fonts for headings and display text; keep body text to safe system fonts
- Test email rendering with web fonts enabled and disabled to verify fallback appearance
- Consider using font-display: swap or optional to prevent invisible text while fonts load
Related Glossary Terms
Dark Mode
Dark mode in email refers to how email clients render messages when the recipient has dark mode enabled. It affects colour display, image rendering, and readability. Designers use CSS media queries and hybrid coding techniques to control the dark mode appearance.
Drag-and-Drop Email Editor
A drag-and-drop email editor is a visual interface that allows marketers to build email layouts by dragging content blocks into place without writing HTML or CSS code.
Email Accessibility Guidelines
Email accessibility guidelines ensure emails are usable by people with disabilities, following WCAG standards for screen readers, colour contrast, keyboard navigation, and readable content.
Email Accessibility
Email accessibility ensures marketing emails are usable by people with disabilities, including those using screen readers, keyboard navigation, or assistive technologies. It follows WCAG 2.1 guidelines for structure, contrast, semantics, and descriptive content.
Attachment
An email attachment is a file sent along with an email message — while common in personal and business correspondence, attachments are generally discouraged in marketing emails due to security, deliverability, and compatibility concerns.
Email Body
The email body is the main content area of an email message, containing the visible text, images, and structural elements that communicate the message to the recipient.
Frequently Asked Questions
Google Fonts — Open Sans, Lato, Roboto, Merriweather, and Playfair Display — are the most commonly used web fonts in email. They are hosted on Google's CDN and supported by most modern email clients that support web fonts. Always pair them with appropriate system font fallbacks.
Yes, web fonts add an HTTP request that can delay rendering, particularly on slower connections. Use a fast CDN, limit font weights and styles, and set appropriate font-display behaviour to prevent invisible text while the web font loads.