How many email clients support background-size?

It works in 17 of 21, partial in 3, not supported in Outlook Classic.

Does background-size work in Gmail Android?

background-size is partly supported in Gmail Android. Closest to Gmail iOS: Gmail Android, which agrees on 273 of the 300 features both are tested on.

background-size in Gmail iOS

Partial background-size is partly supported in Gmail iOS.

Not supported with non Google accounts.

Works in 17 of 21 · partial in 3 · not supported in 1

Which clients

Works: Gmail, Outlook 365, Outlook (New), Outlook iOS, Outlook Android, Outlook for Mac, Apple Mail, Apple Mail iOS, Yahoo Mail Android, Yahoo Mail iOS, Samsung Mail, Thunderbird, HEY Mail, Proton Mail, AOL Mail, Fastmail, Superhuman
Partial: Gmail Android, Gmail iOS, Yahoo Mail
Not supported: Outlook Classic

Your reader in Gmail iOS may not see background-size the way you wrote it, even if it looks right where you tested it.

What to do instead in Gmail iOS

Outlook ignores background-size; use VML or sized images

instead

15 lines

<td background="bg.jpg" bgcolor="#333333" width="600" height="400" valign="top"
    style="background-color: #333; background-image: url('bg.jpg');
           background-size: cover; background-position: center; background-repeat: no-repeat;">
  <!--[if gte mso 9]>
  <v:rect xmlns:v="urn:schemas-microsoft-com:vml" fill="true"
    stroke="false" style="width:600px; height:400px;">
    <v:fill type="frame" size="100%,100%" src="bg.jpg" color="#333333" />
    <v:textbox inset="0,0,0,0">
  <![endif]-->
  <div>Content</div>
  <!--[if gte mso 9]>
    </v:textbox>
  </v:rect>
  <![endif]-->
</td>

Show the original

before

3 lines

<td style="background: url('bg.jpg') center/cover no-repeat;">
  Content
</td>

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What Gmail iOS does with background-size

caniemail record, tested upstream 28 Feb 2019

Partial. Not supported with non Google accounts. But it can be used in the background shorthand property instead.

Your next question

Every feature in Gmail iOS · background-size in every client

Questions

How many email clients support background-size?: It works in 17 of 21, partial in 3, not supported in Outlook Classic.
What do I use instead of background-size in Gmail iOS?: Outlook ignores background-size; use VML or sized images.
Does background-size work in Gmail Android?: background-size is partly supported in Gmail Android. Closest to Gmail iOS: Gmail Android, which agrees on 273 of the 300 features both are tested on.

To see what else in your email Gmail iOS does not support, paste the whole email.

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caniemail (MIT) via @emailens/engine 0.18.22 · tested upstream 28 Feb 2019 · data last changed 10 Nov 2026 · Outlook (New) cells are the engine's mapping