Nearly 50 percent of email users will receive no images when they open your email. This happens when users have chosen to block all images or just images from senders that they have not added to their address book and can mean part of your well-crafted message never makes it to your email subscribers.
HTML ALT tags are used to display a text description of those blocked or suppressed images, or even those that do not display for other reasons. If there are no descriptions of an image that is being blocked or suppressed, not coding your image ALT tags correctly can lead to a confusing message. The chart below shows the percentage of email that arrives with undisplayed images.
There are several reasons for using HTML ALT tags in your email communications:
- Some recipients choose not to load graphics; others may be using mobile devices with slower download speeds or that default to no graphics. Those still on dial-up connections may be looking at your message several seconds before your images load. An Image ALT tag will give these subscribers an idea of what is to come. (Note: 64 percent of key decision makers are viewing your email on their mobile devices, according to MarketingSherpa, in partnership with SurveySampling, 2007.)
- Many email clients have images disabled by default, or display a warning message asking the user if they would like to view the images, or to always view images from 'this sender.'
- Eighty percent of at-work users in the U.S. rely on Outlook and its preview panes (MarketingSherpa 2007). When images that are an integral part of your communication are suppressed, the ALT text used to describe the image may be the only information the recipient will use to decide to open the message.
- Of special note, 38 percent of online consumers now use preview pane for 'capable' email clients, and 64 percent of people who are offered preview panes start using them as their default (MarketingSherpa 2007).
They received your email, now what?
The chart below outlines how email recipients interact with your message if images are turned off based on the type of message that they are receiving. Once you factor in your delivery and open rate, you can see why providing the image ALT tag is an important part of your programming process.
Image ALT tag best practices:
- Avoiding spam: Search engines do not penalize for using ALT tags or even for packing them with keywords. To ensure delivery, you should adhere to the rule of not repeating keywords more than 3-7 times in the ALT tag.
- As a general rule, ALT tags should not be more than 50 characters and should not include special characters.
- If an image contains special/formatted text, simply use the text that is represented within the image.
- For general images supporting content, create a brief description of what the image is; for example: alt="widget in wheat beige" or alt="main header graphic for newsletter"
- For logos, using the ALT text alt="company X logo" is better to describe the image.
- For spacer images, use a simple alt tag, such as alt=".".
- If you are using images as a tool for navigation simply use alt="enter" or alt="left arrow" and avoid special characters.
- If you need to use an image as a link, write the tag to reflect the link that corresponds to the image: alt="http://www.premiereglobal.com/".
One last note
In general, webmail and desktop email clients share the ability to enable or disable images in the user's settings features. Most email clients allow for the immediate download of images within the message if they happen to be suppressed by default. Some email clients have the ability to automatically load images if the sender is known (in the address book of the recipient, don't forget your "add to address link" or instructions to your emails).
Christopher Lovejoy is eMarketing strategist at Premiere Global Services, eMarketing Solutions. .