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Does CSS opacity Work in HTML Email?
Sets the transparency level of an element, from 0 (fully transparent) to 1 (fully opaque).
Quick Answer
Does opacity work in HTML email?
The CSS opacity property is supported in Gmail, Outlook (Mac / Web), Apple Mail, Yahoo! Mail, and others. It is NOT supported in Outlook (Windows). Always include a safe fallback for unsupported clients.
Which Email Clients Support CSS opacity?
CSS support for opacity across email clients
| Email Client | Desktop | Mobile / Web | Notes |
|---|---|---|---|
| Gmail | ✓ Yes | ✓ Yes | — |
| Outlook (Windows) | ✗ No | ? | — |
| Outlook (Mac / Web) | ✓ Yes | ✓ Yes | — |
| Apple Mail | ✓ Yes | ✓ Yes | — |
| Yahoo! Mail | ✓ Yes | ✓ Yes | — |
| Samsung Email | ? | ✓ Yes | — |
| Thunderbird | ✓ Yes | ? | — |
| ProtonMail | ✓ Yes | ✓ Yes | — |
| Fastmail | ✓ Yes | ? | — |
Frequently Asked Questions
Related CSS Properties
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