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Does CSS @keyframes Work in HTML Email?
Defines animation keyframes for use with the animation property.
Quick Answer
Does @keyframes work in HTML email?
The CSS @keyframes property is supported in Outlook (Mac / Web), Apple Mail, Yahoo! Mail, Samsung Email, and others. It is NOT supported in Gmail, Outlook (Windows), ProtonMail. Always include a safe fallback for unsupported clients.
Which Email Clients Support CSS @keyframes?
CSS support for @keyframes across email clients
| Email Client | Desktop | Mobile / Web | Notes |
|---|---|---|---|
| Gmail | ✗ No | ✗ No | — |
| Outlook (Windows) | ✗ No | ? | — |
| Outlook (Mac / Web) | ✓ Yes | ✗ No | — |
| Apple Mail | ✓ Yes | ✓ Yes | — |
| Yahoo! Mail | ✓ Yes | ✗ No | — |
| Samsung Email | ? | ✓ Yes | — |
| Thunderbird | ✓ Yes | ? | — |
| ProtonMail | ✗ No | ✗ No | — |
| Fastmail | ✓ Yes | ? | — |
Notes
- #1 Not supported. The `@keyframes` declaration is kept but values are incorrectly prefixed.
- #2 Partial. Only supports from and to keyframes. Does not support % keyframes
Frequently Asked Questions
Related CSS Properties
Test Your Email Now
Paste your HTML and see how it renders in clients that don't support @keyframes.