Yes, yet another test, and I will return to the rest of the link development series soon, but I have been sitting on this test for some time and I thought you deserve to see the results.
The last test on the value of image optimization was limited to Google and Yahoo only and utilized the title and alt attributes in image links. This is a bit different and only utilizes these elements when the image isn’t a link and it uses four different images with these elements so we have multiple sources to test on the same page. This will give us the opportunity to see if one of these elements might have no weight whatsoever.
So, let’s get to it.
Here are the details of the of the test:
- Four pages have been built with the same four images.
- Each page was given a non-descriptive name, unrelated to the any of the four targeted keywords or any topical relevance and a topically relevant H2.
- Each of these pages have the same parent page, this was given a topical name, related to each of the targeted keywords by topical relevance only.
- Hotels – H-Parent
- Each of these pages contain four images and they have been named for their respective keyword along with a H3 tag with the same keyword.
- Each of the images contain the following elements:
- Alpha – no alt, no title
- Beta – alt, no title
- Charlie – no alt, title
- Delta – alt, title
- The parent of these pages will be located on a rarely visited page (my html sitemap) by users and crawled regularly by search engine spiders.
- These page will target the following keywords:
- Ramada
- Radisson
- Marriott
- Hilton
- Each of these pages were set to publish at the same time in the future, schedule for: Feb 23, 2009 @ 00:01, to ensure each page was available at the same time.
- When cached by all major engines, we will conduct a site search for the priority of pages in the SERPs across all engines for each of the targeted keywords. This will measure the impact of alt and title elements by seeing which of the pages ranks higher with no external impacts.
This being said, here are the results:
| Ramada | |||
| Position | Yahoo! | Bing | |
| 1 | Beta – Alt, |
Alpha – |
Beta – Alt, |
| 2 | Alpha – |
Beta – Alt, |
Alpha – |
| 3 | Charlie – |
Delta – Alt, Title | Delta – Alt, Title |
| 4 | Delta – Alt, Title | Charlie – |
Charlie – |
| Radisson | |||
| Position | Yahoo! | Bing | |
| 1 | Beta – Alt, |
Alpha – |
Beta – Alt, |
| 2 | Alpha – |
Beta – Alt, |
Alpha – |
| 3 | Charlie – |
Delta – Alt, Title | Delta – Alt, Title |
| 4 | Delta – Alt, Title | Charlie – |
Charlie – |
| Marriott | |||
| Position | Yahoo! | Bing | |
| 1 | Beta – Alt, |
Alpha – |
Beta – Alt, |
| 2 | Alpha – |
Beta – Alt, |
Alpha – |
| 3 | Charlie – |
Delta – Alt, Title | Delta – Alt, Title |
| 4 | Delta – Alt, Title | Charlie – |
Charlie – |
| Hilton | |||
| Position | Yahoo! | Bing | |
| 1 | Beta – Alt, |
Alpha – |
Beta – Alt, |
| 2 | Alpha – |
Beta – Alt, |
Alpha – |
| 3 | Charlie – |
Delta – Alt, Title | Delta – Alt, Title |
| 4 | Delta – Alt, Title | Charlie – |
Charlie – |
My initial assumption was that the title element has little, if not no value, however, based upon the results of this study, it appears that this is not the case.
Digesting the Results
First, one of the first things to recognize is that results were consistent for each keyword in each engine. This let’s us be sure (at least within this test) that each engine values each element and combination differently. Each use of alt and title element have a value (even if it is minimal).
Ranking in order:
– Alt Only
– None
– Title Only
– Both
The alt element definitely has the most weight, but it looks like the title element might have a negative affect on ranking and it appears (to me) that use of both may get an over optimization penalty. Interestingly, Google ranked the use of both elements in the last test (which were image links) as it’s first result and alt only as second, so, it is reasonable to say that if you are trying to rank better in Google, then using the alt element for your images will be the best behavior.
Yahoo
Ranking in order:
– None
– Alt
– Both
– Title Only
The most interesting of all of the search engine’s results, Yahoo ranks the use of alt and title elements below the no use at all, but the title element ranked lowest. So, it is reasonable to say that the alt element has the most weight and the title element might have a negative impact on rankings. Even better, Yahoo ranked differently in the previous test, as did Google, using the title only ranked first before and fourth in this test; however, using the alt element ranked second for both tests. If you are trying to rank better in Yahoo, then using the alt element will have the best affect, ranking second in both tests.
Bing
Ranking in order:
– Alt
– None
– Both
– Title Only
Again, the alt element shows to have the most weight, and, once again, it appears that the use of the title element may have a negative value from Bing. Unfortunately, we don’t have details from the previous testing because Live Search failed to crawl and index all of the pages for the first test.
Outcomes
The first thing to consider is users, as it always should be. 508 Compliance is an extremely important thing to understand and adhere to, for more information go to Section 508. Basically, use of alt elements and accurately describing the image is the right thing to do.
Second, based upon the results of both tests combined, the alt element has the most weight in all engines. Using the alt element only will give you top rankings for non-linked images in Google and Bing and second in Yahoo. For linked images, it ranks second in Google and Yahoo.
If you are trying to get the most from your images, linked or not, here is the order of value:
ALT only – Average Position 1.60
None – Average Position 2.4
Both – Average Position 3.00 tie
Title only – Average Position 3.00 tie
If you are trying to get the most from your non-linked images, here is the order of value:
Alt only – Average Position – 1.33
None – Average Position – 1.67
Both – Average Position – 3.33
Title Only – Average Position – 3.67
If you are trying to get the most from your linked images, here is the order of value:
Alt only – Average Position – 2.00 tie
Title only – Average Position – 2.00 tie
Both – Average Position – 2.50
None – Average Position – 3.5
My thought is to include the alt element and forget about trying to add more value by using the title element, it looks like it is more effort than it is worth (which is little).
What are your thoughts?
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- What is SEO? part 3
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I would actually think that alt+title would be better than just the alt. I was extremelly impressed with your research. I am doing a SEO experiment myself and I find this very useful.
Bruno SEO
Interesting demonstration with very interesting results. I’m also surprised that alt+title did so poorly. Glad you mentioned 508 compliance – do you think alt is weighed more heavily because of its usability purpose?
Awesome post, I actually just started using the title attribute along with the alt in some of my sites… so it’s nice to some actual results from you doing exactly that. I do believe I’ll stop this practice, it probably wasn’t worth the time to begin with; but to see that it could actually have a negative effect really makes up my mind. Thanks again!
Great findings. Just hope that google does not change the search algorithm again.
Great work.Hats off to the research you have made.Many facts were completely new to me.I always preferred alt tag and realized how useful it was now.Hope Google stays with the same algorithm.
Very interesting, though I personally think that some things could have been done better. Using links in order to get the pages / images indexed isn’t optimal. The links itself have a big influence on the final results. It probably is way more accurate to only use an XML sitemap in order to get the pages / images indexed. Keep on testing!
Well Written dude..
I am going to take a Print of this article. Such a Nice detailed report which goes through every aspects of Image Optimization. I learned something extra from your article.
Thanks a lot.
Great article. Yeah i agree that image optimisation really helps your site get good SEO reputation in front of search engines.
I have to say you are very brave to attempt to make sense out of the Google system.
People who actually work there certain don’t have a clue. With approximately 200 elements (changing constantly) that go into evaluating a web site, the two people I know who work for Google tell me it is a waste of time for them to try to gauge what elements might be stronger or weaker one week to the next. They also discount page rank as meaningful either. They say that at one time page rank might have had some general relationship to search results but that they are surprised that it is still be offered considering the changes that take place every day at the Google offices.
However, anyway, you are a better man than I am for trying. (Obviously)
Beth
A very interesting study and it is very good SEO optimization may help in promoting the site. Thanks a lot.
I will now have to delete all my TITLE tags from images, i was using both, the title and the alt elements. Thanks for the test!
I can’t help but wonder if your results actually reflect what’s happening in Google, Yahoo and Bing. In this test, the use of both the alt and title tags in an image tag has resulted in an apparent penalty. But is it the use of both tags, or some other factor?
For example, perhaps the lack of keyword density from other sources (e.g. the page text) has pushed the second occurence of the keyword beyond some arbitrary value and triggered the penalty.
I think it would be interesting to run the test again, but this time with the following varients…
1. Lots of keyword relevant text so the alt and title tags don’t stand out
2. The use of different keyword phrases in the alt and title tags (i.e. non-duplicates)
The result of such a test would either lend weight to the theory that both alt and title negatively impact on a site’s ranking, or refute it.
Thank you for this research? I’ve always told people and colleagues to never use the title-attribute when using images. That is what the ALT-attribute is for. Using both is just completely redundant.
Using the title-attribute for links however… now that is completely logical. The title attribute is meant to be used to elaborate further on the linked text.
Many of us already consider optimizing images for Web use by reducing the file sizes as much as possible without noticeable visual degradation.
Do you know, thats totally blown me away… just proving that less is sometimes more! There has always been a ‘fuzzy cloud’ over the subject of the use of the alt tag on images, but the fact that adding a title tag will actually have a negative ‘over-optimised’ scoring effect.
Thanks very much and I think i can safely put the subject of ‘image optimistation’ to bed!!
Interesting.. hopefully someday Google, Bing, and Yahoo will get on the same page
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