Home Resources Blog

We’ve got an updated blog post on ALT text display in email clients – read it here.

So off I went to test how ALT text displays in common email clients, only to find that many of them don’t display any ALT text whatsoever. Unbelievable. And to top it off a couple clients replace the author-defined ALT text with their own idea of ALT text should be (tsk tsk). But before we look at the “how,” let’s look at the “why” in ALT text.

Why ALT Text?

Any web designer attentive to accessibility understands the benefits of ALT text. It’s cardinal purpose, of course, being that it briefly describes an image to someone who is visually impaired via a screen reader. Screen readers read all of the text on a page, denoting lists, links, headlines and ALT text in images. For example, when loading markwyner.com a screen reader would read something similar to the following:

Webpage: Mark Wyner Design, Web Design Studio—Portland, Oregon.
Link 1: Navigate directly to content.
Page headline, link 2: Mark Wyner Design.
Sensible design. Accessible content. Usable interface.
Global navigation.
Home.
Link 3: About.
Link 4: Services.
Link 5: Portfolio.
LInk 6: Contact.
[…]

Note how the screen reader announces the page headline and all links, referencing the latter with numbers. Image ALT text is also read aloud, prefaced with the announcement that the forthcoming text is a text alternative to an image. So the following image:

<img src="https://www.campaignmonitor.com/assets/uploads/file.jpg" width="528" height="405" alt="[photo: bowler picking up a Greek Church]" />

May be read as:

Image: Bowler picking up a Greek Church

A secondary purpose, however, is to describe an image to someone who can not or chooses not to view images in their browsing device or email client. Sadly, the latter doesn’t always work out because many browsers/clients either do not render ALT text when images are disabled or render their own variations thereof. In this article I’ll outline how common email clients display (or don’t display) ALT text.

Clients Used in Tests

Webmail

  • Yahoo Mail
  • Yahoo Mail Beta
  • Windows Live Mail
  • Gmail
  • .Mac
  • Hotmail

Desktop

  • Apple Mail
  • Thunderbird
  • Outlook 2007
  • Outlook 2003
  • Outlook Express
  • Eudora
  • Lotus Notes

Results

A trait shared among all email clients—webmail and desktop—is the ability to disable or enable images by default. And nearly every client in my test suite enabled me to load images directly from the message if they were disabled by default. The exception is Windows Live Mail in which images are loaded for known senders and disabled for unknown senders, the latter scenario exhibiting a link to enable them on the fly. These preferences may be more robust/flexible, but I just tested the basics.

ALT Text Display in Common Email Clients
Client Renders ALT Text Comments
Yahoo Mail No N/A
Yahoo Mail Beta Yes Applies CSS font-styling to ALT text
Windows Live Mail No N/A
Gmail Sometimes Contingent upon text length
.Mac Sometimes Contingent upon text length
Hotmail No N/A
Apple Mail No Replaces ALT text with question-mark icon
Thunderbird Yes Applies CSS font-styling to ALT text
Outlook 2007 Sort of Replaces ALT text with security message
Outlook 2003 Yes Applies CSS font-styling to ALT text
Outlook Express Yes Applies CSS font-styling to ALT text
Eudora Sort of Replaces ALT text with URL to image

Yahoo Mail

Displays ALT text: no

[screenshot of ALT text rendering in Yahoo Mail]

Yahoo Mail Beta

Displays ALT text: yes

The interesting thing about Yahoo Mail Beta is that applies contextually relevant CSS to the ALT text itself. So although it displays ALT text, the potential problem is that large font sizes can push the information beyond the visible border of the image box, rendering it unreadable. But this is, of course, a naturally occurring problem across the board, especially with smaller images and larger descriptions.

[screenshot of ALT text rendering in Yahoo Mail Beta]

Windows Live Mail

Displays ALT text: no

[screenshot of ALT text rendering in Windows Live Mail]

Gmail

Displays ALT text: sometimes

Initially, Gmail only displayed some of my ALT text and I couldn’t figure out why. Further testing yielded the conclusion that text length was the deciding factor. Whereas most clients display what text they can within the boundaries of a box, Gmail decides that if the text extends beyond the said border it will display nothing. Nice.

[screenshot of ALT text rendering in Gmail]

.Mac

Displays ALT text: sometimes

.Mac suffers parallel to Gmail when rendering ALT text, in that it reserves text-length contingencies.

[screenshot of ALT text rendering in .Mac]

Hotmail

Displays ALT text: no

[screenshot of ALT text rendering in Hotmail]

Apple Mail

Displays ALT text: no

The clients which do not display ALT text typically display gray boxes in place of the images. Apple Mail, however, displays open space and adds a little question-mark icon. I’m an emphatic fan of Apple products and have been using them for roughly 15 years now. Their products are always very usable and beautifully aesthetic. But I must admit that for obvious reasons it was an ill decision to replace images with a question-mark icon. While this isn’t perilous, it is something to note nonetheless.

[screenshot of ALT text rendering in Apple Mail]

Thunderbird

Displays ALT text: yes

As with Yahoo Mail Beta, Thunderbird applies contextually relevant CSS to ALT text. Again, there are no paramount consequences of this result, but it’s noteworthy all the same.

[screenshot of ALT text rendering in Thunderbird]

Outlook 2007

Displays ALT text: sort of

I’ll bite my tongue and stick to the facts on this one. Outlook 2007 prefaces all ALT text with its long-winded explanation of why an image was omitted from a message: “Right-click here to download pictures. To help protect your privacy, Outlook prevented automatic download of this picture from the internet.” This falls down in two very specific ways. First, this is the kind of message which should merely introduce someone to a feature. To repeat it for every image in every email indefinitely is a plethora of information. Second, it pretty much wipes out any ALT text which follows it, given the length of the preface and the average image size in an email.

[screenshot of ALT text rendering in Outlook 2007]

Outlook 2003

Displays ALT text: yes

While Yahoo Mail Beta and Thunderbird apply CSS font-size and color properties to ALT text, Outlook 2003 only applies color. I can’t think of a scenario wherein this would have a negative impact, but I feel it’s still relevant to my findings. Outlook 2003 is also the origin of the security-message-replacement woes of Outlook 2007.

[screenshot of ALT text rendering in Outlook 2003]

Outlook Express

Displays ALT text: yes

Outlook Express is parallel to Outlook 2003 regarding CSS font-properties.

[screenshot of ALT text rendering in Outlook Express]

Eudora

Displays ALT text: sort of

Eudora replaces ALT text with an absolute URL to the location of a respective image. I assume this informs a reader where the image can be found, if they feel so inclined to view the image in their browser. But given that the path to the images is truncated, I’m left pondering the value of this system.

[screenshot of ALT text rendering in Eudora]

Lotus Notes

Displays ALT text: ?

I attempted to get results for Lotus Notes but was unsuccessful in disabling images for the test. I found settings to disable images, but the setting yielded no changes in how images were displayed. I even sent a test to one of my clients who I know uses Lotus Notes at work every day. He, too, could not disable images. If someone can share this information, I’ll update the article to include Lotus Notes results and accompanying screen shot.

This blog provides general information and discussion about email marketing and related subjects. The content provided in this blog ("Content”), should not be construed as and is not intended to constitute financial, legal or tax advice. You should seek the advice of professionals prior to acting upon any information contained in the Content. All Content is provided strictly “as is” and we make no warranty or representation of any kind regarding the Content.
Straight to your inbox

Get the best email and digital marketing content delivered.

Join 250,000 in-the-know marketers and get the latest marketing tips, tactics, and news right in your inbox.

Subscribe

See why 200,000 companies worldwide love Campaign Monitor.

From Australia to Zimbabwe, and everywhere in between, companies count on Campaign Monitor for email campaigns that boost the bottom line.

Get started for free