The ALT attribute is one of those bits of code that's been abused since day one. People can't remember it's name, they stuff it full of keywords or they ignore it entirely. So with my tongue planted firmly in my cheek, I thought it might be fun to create a graphic that tells you what you need to know about using the ALT attribute.

With that in mind, here's my visual representation of the four primary reasons to use the ALT attribute.


Let's break these down a bit further by quadrant.

Text Only Browsers

textonly.gifBack when the ALT Attribute was originally created, its primary purpose was to serve users of text only browsers like Lynx. Surfers would browse a site and would be served up text-only content. Where an image might have appeared, the text browser displayed the alternative text.

While it's true that very few people surf the web with text-only browsers these days, there are people who still pay for their Internet usage by bandwidth who choose to turn images off. Since it's always a good idea to design for the masses but consider the minorities, it's simply good practice to make proper use of this attribute.

Accessible Browsers

accessible.gifPerhaps the most important reason to make use of the ALT attribute these days is to assist visitors who rely on accessible browsers to help them navigate the web. Visually impaired readers rely on software that reads the content of a site to them. When this software comes to an image, it checks the content of the ALT attribute and reads the content as part of the page.

(Note: This is why it's essential to make proper use of the ALT attribute instead of trying to shove it full of keywords to help your rankings. Imagine the frustration of a visually impaired user being forced to listen to an endless string of keywords every time their screen reader runs across an image on your site.)

Matt Bailey of Site Logic Marketing does a great job of showing what happens when you try to stuff keywords into your ALT attribute during his talks on accessibility by playing an audio file of a screen reader on a keyword stuffed site.

Mobile Browsers

mobilebrowser.gifWhile it's true that smart phones are quickly equipping the Internet addicted public with true browsers and quick access to the web, a good deal of web-enabled phones still rely heavily on the ALT attribute. There are several reasons for this.

First, many web-enabled phones operate with an extremely limited browser. Second, some of these browsers time out early on images and some simply don't display them at all. Third, a decent portion of people who own these phones still pay for Internet access based on bandwidth so many choose to surf with images off to keep their phone bills down.

Search Engines

searchenginealt.gifOf course web enabled phones and accessible browsers and text only browsers still aren't going to be enough to convince everyone to use the ALT attribute. That's where search engines come into play. Yes, the search engines read and consider the words in your ALT attribute. No, they don't play a major role in impacting your rankings.

That said, they certainly aren't going to hurt your rankings and a well crafted ALT attribute will serve the three groups I mentioned above AND will be considered by search engines, so why on earth would you ignore them? Even beyond the standard search engine listings, you need to consider image search. More and more people are taking advantage of image search these days and the engines look to things like the ALT attribute, image tags, surrounding text and the like to decide which images to display.

There's a long tail of image search as well and making proper use of your ALT attribute can go a long way toward helping you pick up the traffic.

A Few Final Notes About the Alt Attribute

1.) While it's a good idea to include a descriptive alt attribute for the graphics on your web site, it's perfectly fine to leave the alt attribute blank for an image that is purely decorative. (When I say blank, I don't mean leave it out...I simply mean leave it empty. You need an ALT attribute if you want your code to validate.) There's no reason for those decorative images to find their way into image search engines and users with accessible browsers likely don't want to hear "pretty image" repeated over and over as they surf your web site.

2.) No, the alt attribute is not called "the alt tag," despite what you'll hear coming out of the mouths of otherwise code savvy individuals. (Even I slip up and call it that now and then.)

3.) ALT is short for "alternative." The alt attribute is for offering up a word-based alternative to the image you're presenting. Imagine you're reading the page to a friend out loud. What would you say to describe the image when you get to it? There's nothing wrong with having some keywords in there, but remember the primary function of the alt attribute is to describe the image.

September 4, 2008

Jennifer Laycock is the Editor of Search Engine Guide, the Social Media Faculty Chair for MarketMotive and offers small business social media strategy & consulting. Jennifer enjoys the challenge of finding unique and creative ways to connect with consumers without spending a fortune in marketing dollars. Though she now prefers to work with small businesses, Jennifer’s clients have included companies like Verizon, American Greetings and Highlights for Children.


Hey Jennifer, your image showing the four primary reasons to use the ALT attribute did not have an alt atribute. The four quadrant image files didn't either.

I'm just trying to help. It's what I do. :)


A great all around SEO post on the many benefits of using Alternate Text in your images.

Great article thanks.

I had a question about using title tag in case of links and images on a webpage. How important are these tags and how do they help.

A picture is worth 1000 Alt tags

I'll take what I can get as I found this article helpful indeed.

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