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
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Adaptive Design
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AI-Generated Content in Email
AI-generated content in email is copy, images, code or subject lines produced by artificial intelligence tools to speed up campaign production and testing.
Alt Text
Alt text is the written alternative to an image in an email, displayed when images are blocked, slow to load, or consumed by screen readers.
Autoplay Video in Email
Autoplay video in email refers to the limited ability to play video content automatically when an email is opened, using specific client-supported techniques.
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.