CSS Properties

transition

CSS property · 5 supported, 7 partial, 9 unsupported across 21 clients

Client Support

Client	Category	Engine	Support
Gmail	webmail	Gmail Web	Unsupported
Gmail Android	mobile	Gmail Mobile	Unsupported
Gmail iOS	mobile	Gmail Mobile	Unsupported
Outlook 365	webmail	Outlook Web	Unsupported
Outlook (New)	desktop	Outlook Web	Unsupported
Outlook Classic	desktop	Microsoft Word	Unsupported
Outlook iOS	mobile	Outlook Mobile	Unsupported
Outlook Android	mobile	Outlook Mobile	Unsupported
Outlook for Mac	desktop	WebKit	Unsupported
Apple Mail	desktop	WebKit	Supported
Apple Mail iOS	mobile	WebKit	Supported
Yahoo Mail	webmail	Yahoo	Partial
Yahoo Mail Android	mobile	Yahoo	Partial
Yahoo Mail iOS	mobile	Yahoo	Partial
Samsung Mail	mobile	Samsung	Partial
Thunderbird	desktop	Gecko	Supported
HEY Mail	webmail	WebKit	Partial
Proton Mail	webmail	Proton	Supported
AOL Mail	webmail	AOL	Partial
Fastmail	webmail	Fastmail	Supported
Superhuman	desktop	Blink	Partial

Client-by-client behaviour for transition

Fully supports transition (5): Apple Mail, Apple Mail iOS, Thunderbird, Proton Mail, Fastmail.

Partial support (7): Yahoo Mail, Yahoo Mail Android, Yahoo Mail iOS, Samsung Mail, HEY Mail, AOL Mail, Superhuman. Expect rendering quirks unique to each engine. Partial support typically means a subset of values, an ignored shorthand, or sanitizer-specific rewrites.

No support (9): Gmail, Gmail Android, Gmail iOS, Outlook 365, Outlook (New), Outlook Classic, Outlook iOS, Outlook Android, Outlook for Mac. Plan fallbacks for these clients before relying on transition in production sends.

Fixes & Workarounds

Gmail

Unsupported

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

Gmail Android

Unsupported

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

Gmail iOS

Unsupported

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

Outlook 365

Unsupported

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

Outlook (New)

Unsupported

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

Outlook Classic

Unsupported

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

Outlook iOS

Unsupported

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

Outlook Android

Unsupported

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

Outlook for Mac

Unsupported

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

Yahoo Mail

Partial

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

Yahoo Mail Android

Partial

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

Yahoo Mail iOS

Partial

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

Samsung Mail

Partial

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

HEY Mail

Partial

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

AOL Mail

Partial

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

Superhuman

Partial

CSS transitions are not supported in email.

Before

.button {
  background-color: #6d28d9;
  transition: background-color 0.2s;
}
.button:hover {
  background-color: #5b21b6;
}

After

.button {
  /* Use the most visually appealing state as default.
     :hover is only supported in a few clients. */
  background-color: #6d28d9;
  color: #ffffff;
  text-decoration: none;
  font-weight: bold;
}

Transitions don't work in email — style the default state well

Production guidance for transition

transition is a CSS property. Across the email client matrix, 5 of 15 tracked clients support it fully, 7 only partially, and 9 not at all. The clients most likely to require a workaround for this feature are Gmail, Gmail Android, Gmail iOS. Each of them needs a tailored fallback. See the per-client examples above for the specific code fix Emailens recommends.

When in doubt, ship a baseline that renders without transition and treat it as progressive enhancement on clients where support is verified. Emailens automatically detects cross-client divergence on this feature when you preview an email, so you can see exactly which template paths break before a campaign goes out.

Related Features

!important accent-color align-items animation aspect-ratio backdrop-filter background background-blend-mode

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Support data last updated Apr 27, 2026 · synced from caniemail.com via @emailens/engine.