Does img alt-attribute have equal relevance as normal text in h1?

Question

There is a question that bothers me for quite some time. I have read quite a few articles, but gotten no fully satisfying answer.

The Problem: I have an Image with the Company Logo placed at the top of a website.

Now, is

<h1><img ... alt="My HP-Title"></h1>

in terms of SEO equivalent to

<h1>My HP-Title</h1>

For long time I used the technique using the logo as background-image and text-indent:-100em the companies name, but that might be considered as black-hat SEO, so I abandoned that.

On the other hand, even W3C uses a hidden span for the title, so perhaps it doesn't matter at all?

Answer 1

It's essentially up to the search engine. But they should be threated the same way, if the browser (or here: the spider) doesn't support images. There's no perfect way to solve the whole question, because in the end you don't know how the search engine will interpret or judge your code. It might ignore the alt attribute, but it might as well ignore the empty span. Also don't use text alignment to hide text, it might screw up rendering on mobile browsers or browsers interpreting it in a different way (e.g. adding scroll bars to scroll there or resizing the whole page).

The question I'd ask here is: Do you even need the image? Using new standards (CSS2/3, SVG and WOFF) there are lots of possibilities to do most stylized headlines with plain html that won't confuse search engines or let them think you're trying to confuse them.

Answer 2

I would strongly suspect that visible text is considered more important than the hidden alt text.

As Mario said. If possible avoid using images for text.

There are also some JavaScript libraries that can dynamically replace text with an image of the text.