ALT Tags & SEO

[wshall]

Forum members,

Could I get your opinions about using Alt tags for SEO keywords? I'm seeing some disagreement over their value.

Jill Whalen (whose SEO primer is great) wrote the following in her article, Ten Tips to the Top of Google http://searchenginewatch.com/searchday/article.php/2198931 :

7. Use extra "goodies" to boost rankings. Things like headlines, image alt tags, header tags <H1><H2>, etc.), links from other pages, keywords in file names, and keywords in hyperlinks can cumulatively boost search engine rankings. Use any or all of these where they make sense for your site. [Bold highlighting added]

I’m seeing some alternative views, however, when I read the URL Spaces & Alt Tag Naming Conventions thread http://forums.searchenginewatch.com/showthread.php?t=1734 . This thread is promoted in the common questions “sticky” thread. In it, Incubator says,

As for the alt tags they really wont matter, most crawlers ignore them and it really only aids if the pics dont load, so on the note, make any descriptions there as specific to the pic in general.

Does anyone have any test results to show which opinion is correct?

Thanks,

Scott

[mcanerin]

I've tested it and as of very recently, ALT tags are considered by all 4 major engines. Not too long ago, Google would only consider them if the alt tag was in a link and therefore considered anchor text.

Having said that, it only seems to make a difference if the keyword is very uncompetitive - in short, it might put you in the pile of results, but it's at the bottom.

The best practice would appear to be to use them, and to put appropriate keywords in them as long as they actually describe the picture (ie putting a bunch of keywords in an invisible gif or a 1x1 pixel graphic or whatever is still spam) but they appear to help a bit if used appropriately.

They won't help your site much in a very competitive area, but they will help people find you if you are a photographer and have a primarily image based site, for example.

Use them, but use them wisely. Remember that people with disabilities visiting your site should not be subjected to an hour of the same keywords being repeated to them over and over again via a screen reader. That's bad.

But if you site looks good in a text only browser while showing them, then you've done a good thing - for users and search engines.

As for Jill and Incubator, they were both correct when they said what they said, but the search engines don't stand still... ;)

Ian

[wshall]

Thanks, Ian! I appreciate the fast reply and the results of your testing!

May I ask two follow-up questions? One is regarding the Alt attribute in the anchor tag, the other is a related question about the anchor tag's title attribute.

First, regarding the Alt attribute. You mentioned in your post that,

Not too long ago, Google would only consider them if the alt tag was in a link and therefore considered anchor text.

I'm asking because I don't see that the Alt element would be valid HTML for the <a> tag. (I'm no expert on that, so I consulted a few references... they seem to indicate that the "title" attribute would be valid for use in an <a> tag.)

If the spiders score it, then I would probably break the HTML rules and use this... but I'm worried that the HTML validators may barf over this item. Any experience or testing regarding this use of an Alt attribute in the anchor tag?

The second question is on a related topic... has anyone tested the impact of using keyword phrases in the "title" attribute?

Thanks!

Scott

[softplus]

I'm asking because I don't see that the Alt element would be valid HTML for the <a> tag. (I'm no expert on that, so I consulted a few references... they seem to indicate that the "title" attribute would be valid for use in an <a> tag.)

I use alt-tags like this - it works for me (I've been testing that for about a month now, all major SEs picked it up):

<a href="linkto....."><img alt="here is my alt text" src="http://here-is-my-image.jpg"></a>

In my tests, I could not get the title-attribute within the a-tag to rank in the SEs, but perhaps others have had some luck with that - at any rate, I like to include it, if only for the users out there who have compliant browsers :-).

[mcanerin]

To answer your questions:

re: title attribute

No, it's not indexed. - only the alt attribute. Now before some lurker (yeah YOU over there - I see you...) comes back and starts talking about how titles are important, yadda yadda, because they didn't bother to read this thread or whsall's question, I'm gonna make something clear:

We are talking about the title attribute for images, not the title tag for web pages. Now pay closer attention next time.

As for your second question, I think your sources are confused :)

This is good and indexable:

<img src="mypic.gif" width="50" height="40" alt="A pretty picture">

This is not:

<img src="mypic.gif" width="50" height="40" title="A pretty picture">

As a matter of fact the "title" attribute is not supported well for images (though it's a valid attribute). When it is supported, it usually shows up as a "Tooltip" on a mouse hover, such as in IE.

There is something similar you might be thinking about called the "LongDesc" but to anticipate your next question we've checked that and it's not indexed either. :)

Alt only.

Ian

[Chris_D]

has anyone tested the impact of using keyword phrases in the "title" attribute?
Yes - my research indicates that search engines ignore the title attribute. The title attribute can be used on e.g. images or links etc. (NOTE - as Ian said above - we are talking about the title attribute - NOT the title element - the title element is very important).

Try it yourself. Look at the Google text cache for a page using e.g link title tags and imagle alts; or image titles which are different to the image alt. You can see the alts in the Google text cache - where are the title attributes?

But even worse still - title attributes aren't used by most talking browsers!!

Most users of screen reader software will not be aware of the TITLE text, some will not be not able to read the TITLE text even if they know it is there.
There is some recent Australian research on this which I saw at the WE05 conference last week - http://www.sf.id.au/WE05/survey.html

[wshall]

Ian,

Thanks for the the second reply. I think I was misunderstanding what you said in your first post. When you said,

Not too long ago, Google would only consider them if the alt tag was in a link and therefore considered anchor text.


I thought you were meaning an alt element to the <a> tag. :rolleyes: Reading your response, I'm thinking you mean that Google only considered it if the image was surrounded by an <a> tag...
i.e., <a href...><img src=myimage.gif alt="Keyword phrase"></a>

If I'm understanding right now, that explains why Softplus says,

I use alt-tags like this - it works for me (I've been testing that for about a month now, all major SEs picked it up):

<a href="linkto....."><img alt="here is my alt text" src="http://here-is-my-image.jpg"></a>

But Ian, you're saying that your tests show that the major engines are now picking up image-tag alt elements without the surrounding-anchor-tag trick.

I don't want to be redundant here... just summarizing in case some other person like me comes along and reads this thread.

Do I have this right?

Thanks again for all your advice on this!

Scott

[mcanerin]

You are correct - Google has treated alt text as anchor text if the image was in a link for some time now, but recently have also been looking at alt text as just plain alt text.

They did at first, but then people started stuffing keywords in them so they stopped for a while. Now they do again, but there are apparently rules to how many characters are indexed, etc.

So it's not a free-for-all, like the old days, but they have recognised that there is a legitimate need to index alt text. Just don't pin your hopes and dreams on it - it doesn't help too much, but it does help a bit.

Ian

[softplus]

On a similar note, how would you best optimize a page with ONLY graphics in it (eg. all of the text within the graphics)? Should you go through the meta description or image alt-tags? Or both (with different texts)? Or even - just asking - invisible text on the page (html comments probably don't work)?

(Yes, I know it's even better to remake the page to have the text in html, but some people have impossible budget for this type of stuff :D)

[mcanerin]

If I was stuck with that scenario, I'd use a combination of page titles, alt text for the pictures, and IBL anchor text, with as much use of "captions" (ie visible text) for the pictures as possible or practical.

I'd also make certain that every picture that was important enough to warrant keywords was also clickable (ie a link) if possible or practical.

Finally, I'd make sure I used other things like the keyword and description metatags - though it's not likely to help much, in this type of case you pretty much take anything you can get ;)

But I wouldn't be too happy about missing half my toolkit (the content). You can get good rankings for this type of site, but it's more challenging - kind of like optimizing for Flash.

Ian

[softplus]

Thanks Ian, that's good advice!
Cheers
John

[GBR&D]

If I was stuck with that scenario, I'd use a combination of page titles, alt text for the pictures, and IBL anchor text, with as much use of "captions" (ie visible text) for the pictures as possible or practical.

I'd also make certain that every picture that was important enough to warrant keywords was also clickable (ie a link) if possible or practical.

Finally, I'd make sure I used other things like the keyword and description metatags - though it's not likely to help much, in this type of case you pretty much take anything you can get ;)

But I wouldn't be too happy about missing half my toolkit (the content). You can get good rankings for this type of site, but it's more challenging - kind of like optimizing for Flash.

Ian

I agree, good advice.

[TallTroll]

I've seen Google using Alt content as one of the options in their "mini-sitemap" UI experiment

Theres a page where a term appears ONLY as alt text for an image that is a link, and it is offered as one of the extra links. I believe it has been picked up because the image link is pointing at a high authority page

[mocgiit]

How many keyword should be put in the alt tags as a rule of thum. One important one. Or just a keyword phrase. Also if the is more than one keyword how should you seperate them with a dash or underscore?

[mcanerin]

The Alt tag of a picture is intended to provide a text equivalent of an image. Note I didn't say "description". In most cases, it's the same thing, but there are exceptions.

In some cases, there are no keywords that would fit. As a general rule, you would try to create an accurate text equivalent, but using keywords where you can do so reasonably.

The most number of characters that Google will index in an alt tag currently appears to be 125, but as a practical matter you should not usually get anywhere near that.

In general, use as much as you need to do the job, and not more. I would be cautious about repeating keywords though.

Ian

[mocgiit]

In general, use as much as you need to do the job, and not more. I would be cautious about repeating keywords though.

What do you mean by repeating a keyword. Within the alt tags or the content in general. I thought you were suppose to repeat keywords within pages? I am just a bit unclear.

[mcanerin]

Assume you have a picture of a San Jose realtor named Joe Smith, and you want to add an alt attribute. Just putting "Picture of Joe Smith" would be accurate, but you'd be missing important keywords like "San Jose", "real estate" and so forth.

So you would add in useful and descriptive keywords, without going overboard.

Bad Example:

"A picture of a San Jose real estate agent sitting in a San Jose real estate office looking at a San Jose real estate website"

or

"San Jose real estate agent, San Jose realtor, SJ real estate, SJ realtor, San Jose home, San Jose buy home"

Good example:

"San Jose Real Estate Agent Joe Smith"

Basically, you don't just dump your keyword list into alt attibutes. Instead of just "Joe Smith" you could legitimately add a description like "San Jose Real Estate Agent" to it, which contains keywords. The Alt is still descriptive and easy to understand, but now contains helpful and descriptive keywords.

Ian

[mocgiit]

gottcha. I thought you ment you were suppose to add mutipule keywords within the page. Thanks for clearing it up for me.

[pennsylvania]

so titles are useless when optimizing images for SEO?

[mcanerin]

Title attributes are, yes.

Ian

[pennsylvania]

Does it hurt the site (in terms of SEO) to have them?

Chris Pearson says to use title tags to get indexed by google image search. Is that wrong?

Sorry for all the questions. I do really appreciate that you got back to me on this.

[TallTroll]

>> Does it hurt the site (in terms of SEO) to have them?

No. I have seen evidence that title attributes are used as a ranking metric, but its a VERY small part of the algo

>> Chris Pearson says to use title tags to get indexed by google image search. Is that wrong?

No, not wrong, I don't think, but not crucial either

[jimbeetle]

Brendan lives!

[mcanerin]

I have seen evidence that title attributes are used as a ranking metric, but its a VERY small part of the algo

I haven't, but would be very interested in seeing that information. To date, all the testing I've done has shown it has no effect at all in any of the top 3 search engines.

I also note that Chris thinks you should use underscores instead of dashes in image names (and calls a reader a "dick" for pointing out this is a bad idea). I would not take SEO advice from him based on this post.

The only real advice in this post was to use keywords in the alt attributes of images and in your page titles so Google will know what they are about.

True, but not exactly cutting edge research...

Ian

[Marcia]

Tested with Google just recently, and I can state without any doubt (and document) that the image alt attribute is absolutely, positively, one of the factors used as part of ranking.

[beu]

Tested with Google just recently, and I can state without any doubt (and document) that the image alt attribute is absolutely, positively, one of the factors used as part of ranking.
Totally, for sure, no questions asked, 100%, yes, couldn't agree more, bet on and take it to the bank!

[marketraise]

Now this is what I call a live post really guys you have gathered a great information here I am glad that I joined this forum I am newbie here.I would love to get involved in one such informative discussion.

[TallTroll]

>> I haven't, but would be very interested in seeing that information

It was a while ago, granted, but I saw some results in G where a travel site was ranking for misspelled terms that only appeared in the title attr of an image on the page (it was one of those paragraph long jobs, scraped and spindled and folded).

It was definitely ranking based on that, since there was no other instance of it on the page - but for other "popular" misspells, the page was nowhere. I therefore concluded it is used, but it's a very weak signal (not an unreasonable stance by G, I think)