HTML Elements

<object>

HTML element · 1 supported, 4 partial, 15 unsupported across 21 clients

As of Sep 2, 2026, <object> fails or degrades in 20 of 21 email clients, treat it as progressive enhancement, never structure.

0/7 webmail, 0/6 desktop, 1/8 mobile clients support <object> fully.
Unsupported in Gmail, Gmail Android, Gmail iOS, Outlook 365 and 11 more.
Partial in Outlook for Mac, Apple Mail, Samsung Mail, Thunderbird, behavior differs from browsers, test before relying on it.
Outlook Classic (Word engine, supported to at least 2029) does not fully support <object>, and its replacement changes little here; see the deprecation diff.
Across all clients, only 6 of 298 tracked HTML/CSS features render identically everywhere.

Source: caniemail.com (MIT), via the Emailens engine. Last tested upstream Feb 20, 2021, synced by Emailens Sep 2, 2026.

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	Partial^{See caveat 1}
Apple Mail	desktop	WebKit	Partial^{See caveat 1}
Apple Mail iOS	mobile	WebKit	Supported
Yahoo Mail	webmail	Yahoo	Unsupported
Yahoo Mail Android	mobile	Yahoo	Unsupported
Yahoo Mail iOS	mobile	Yahoo	Unsupported
Samsung Mail	mobile	Samsung	Partial^{See caveat 2}
Thunderbird	desktop	Gecko	Partial^{See caveat 2}
HEY Mail	webmail	WebKit	Unsupported
Proton Mail	webmail	Proton	Unsupported
AOL Mail	webmail	AOL	Unsupported
Fastmail	webmail	Fastmail	Unsupported^{See caveat 3}
Superhuman	desktop	Blink	Unknown

Documented caveats (3)

1.Outlook for Mac, Apple Mail: Partial support. Does not support Videos resources.
2.Samsung Mail, Thunderbird: Partial support. Does not support PDF resources.
3.Fastmail: Not supported. The <object> element and all its content is removed.

Caveats recorded by caniemail.com (MIT) and carried verbatim, one entry per wording rather than per client.

Client-by-client behaviour for <object>

Fully supports <object> (1): Apple Mail iOS.

Partial support (4): Outlook for Mac, Apple Mail, Samsung Mail, Thunderbird. Expect rendering quirks unique to each engine. Partial support typically means a subset of values, an ignored shorthand, or sanitizer-specific rewrites.

No support (15): Gmail, Gmail Android, Gmail iOS, Outlook 365, Outlook (New), Outlook Classic, Outlook iOS, Outlook Android, Yahoo Mail, Yahoo Mail Android, Yahoo Mail iOS, HEY Mail, Proton Mail, AOL Mail, Fastmail. Plan fallbacks for these clients before relying on <object> in production sends.

Behaviour unverified in: Superhuman.