Which is better in links from the search engines’ point of view: plain text or images with an alt attribute that says the same thing? For example, is this:
<a href="">This is a link</a>
better than this?
<a href=""><img src="" alt="This is a link"></a>
SEOs I’ve spoken to before about the subject claim that all links to important sections of your site should be plain text rather than image links. Which means that if you want to give links a particular graphical look that can’t be achieved with plain text, your only other option is to use an image replacement method.
But I wasn’t convinced that search engines (Google at least) viewed the two examples that much differently, so when Maile Ohye, Developer Programs Tech Lead at Google, wrote a post at the Webmaster Central Blog about the Importance of Link Architecture, it gave me the opportunity to ask this very question. Her response was:
We’re pretty capable of detecting image links for crawling purposes. Accurate, not spammy, alt text is beneficial in many ways — it’s helpful to users, not just as a signal to search engines. If you have useful image links (or even just for images) it’s good to make the alt text descriptive.
Tyssen, if your image links are formatted similar to your example, you should be fine.
So it would seem that images of text in links with alt attributes that describe the text is no worse than links that contain that actual plain text as far as Google is concerned. Which also means that image replacement may not be necessary in most situations as the text is still in the page and readable by machines (and people with images turned off).
This is of course just one person’s viewpoint (albeit the view of someone who is better placed than most to comment on the issue), so I’d be interested to hear from others if they have any evidence that either backs up or refutes this assumption, and also whether the other search engines have a different take on it from Google.
I would have guessed that it didn’t matter one way or the other. Just my guess mind you.
Yeah, same assumption as Mike above. I would have assumed that there’s not much different from a search engine’s point of view, but I’m not a master SEO either, so what do I know?
About a year before this was written I worked on a front-end project for Yahoo and they directed me to use the image replacement method for headers. We did not do this for image links. They’re the second biggest player, but things have changed since that time too.
Personally, I am going to continue using that method when it makes sense to do so.
Hi Andy, so you’re saying that for this project images with alt attributes were used in links and image replacement was only used for headings (without links)?
Hi John, thanks for this post.
I use the image replacement technique when I can. However, sometimes you can’t really replace an image because of the visual quality.
I just wrote a post on the same thing SEO Debate: Text vs Image Links.
In my opinion, I think that anchor text would be weighted more than the text used in the alt attribute because its not within another HTML tag.