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SEO for Images

Squirrel

Optimizing images for search engines is a somewhat unique realm of SEO. While many of the same ranking factors that apply for standard search also apply for images, there are additional factors that must be considered to make truly SEO-friendly images.

Optimizing an image for search engines can have up to three objectives. First, you want to get the image ranking well for relevant searches in image search engines such as Google images, Yahoo! Image Search, and Bing Images. This can generate solid traffic. Second, you want the image to add keyword relevance to the page it’s on. For the sake of example, suppose you have an awesome page on squirrels consisting of nothing but images: the search engines won’t have a very good understanding of the content of that page if those images are not search engine optimized. Third, images can be great link bait.

What affects an Images Ranking in the Search Engines?

There’s actually a lot of different things that can affect an images ability to rank highly in image search engines. Let’s review:

Alt text

Alt text, also known as alternate text or the alt attribute, was originally developed to aid seeing impaired people as well as to help websites gracefully degrade for viewing on a text browser (such as a mobile browser.) It is an attribute added to pictures that describes what they portray in words. It can be found in the source code as alt=“___”. It is useful to keep your focal keywords in mind when writing the descriptions. Also, terms that come first may be given slightly higher weight (like in title tags). Keyword rich alt text also raises the relevance of a page for the keywords used, though generally not more than normal html text. Note that keyword-stuffing will not help you.

Image filename

Make sure the image file name is relevant. For instance, rabid_squirrel.jpg would be preferable to frsq_30824749.jpg. Optimizing the file name will help the image rank in image searches as well as raise the relevancy of the page (albeit very slightly). Alternatively, a combinations of descriptive keywords and numbers (such as rabid_squirrel_30824749.jpg), may enable numeric file-naming conventions while still adding some (albeit slightly less) SEO value.

The page the image is on

The page that image is on has a huge impact on whether or not the image ranks well, and there are two main factors here. First, the content on the page is a clue to what the image is about. Text that is in close proximity to the image, such as captions, is especially important. Second, the authority of the page matters. The better the page ranks for a given search term, the better the image on that page will be able to rank for that term.

Links

Newsflash: inbound links are important to SEO. Guess what? They matter for images too! Just like with normal web pages, the image’s importance in the eyes of the search engines is impacted by link factors such as link anchor text, authority of the link source, and quantity of inbound links. So, for example, if you would like to defend your #1 image ranking for the term social media, a link such as the one to the left would help.

A special thing to consider here are “hotlinks.” Image hotlinking occurs when someone links directly to the url the image is hosted on, which is typically fastest way to share someone elses image. While some webmasters don’t like people hotlinking to their image because it may violate copywrite and squat bandwidth, it does constitute an inbound link and thus helps the ranking of the image at its original source.

Image File Size

Neither humans nor search engines like it when the content on a page takes a long time to load. Well, when images have large file sizes, pages generally take longer to load. Generally, search engines only have trouble indexing image files that are really, really huge, so chances are you have no worries here. I honestly couldn’t tell you what exactly when the file is too big, but you generally want to keep image file sizes at a minimum to decrease page load times.

Sitemap

To make sure the search engines index your images, make sure important images are included in the sitemap. You will need to ensure special tags for the images are included in your main sitemap, or you can create a special image sitemap. Learn more about image sitemaps here.

An Example

Let’s examine the image search engine result pages for the query “squirrel.”

Squirrel!Now let’s make some observations here…

  • The first two images are from the Wikipedia page on squirrel. Hundreds of sites link to this page, which has a ton of content pertaining to squirrels and also happens to rank #1 in Google’s standard SERPs for “squirrel.” A perfect example of how the page the image is on matters.
  • The third image is from the home page of a semi-high authority site call project-squirrel.org. The alt text and surrounding text contains use of our keyword. I ran the image url (http://www.projectsquirrel.org/images/home_page_squirrel2.jpg) through the link explorer tool inside Bing Webmaster Tools and learned that there were multiple sites linking to this url. So this image boasts relevance, hotlinks, and decent page authority.
  • The fourth image, the weird mutant-banjo-squirrel, has some keyword relevance though less than the higher ranking images, but has more hotlinks than either one.
  • If you examine these top-ranking photos, you will continue to see, as I did, significant occurrences of inbound links, high page authority, and keywords in alt text, filenames, and nearby text. These factors really make a difference.

Some Image SEO tips

Below are some tips largely made up of recycled material from addressing some of the most common image SEO issues I’ve encountered in clients’ sites.

Pay attention to image links

The anchor text of links is a very important factor in determining the relevant keywords for the page being linked to. For image links, the alt text serves as the anchor text, so alt text becomes extra important for image links. So,  if you use banners or badges, you really want to make sure you are using optimal alt text.

Encourage linking to an image when appropriate

This tip comes from Google itself, “Provide a HTML snippet that other people can use to embed your image on their page while providing attribution. This snippet can include both the link to the image and a link to the source page on your site.” What a great way to help build links to the image, huh?

Watch out for words in images

In general, you want to avoid using images that contain words. But if you must do so, consider re-examining the alt text and making the alt text better match the words in the graphic. Also, if the image with words is a main banner, use a header tag h1 or h2 if it is appropriate to signal to the search engines that they should place additional importance on the alt text as a relevance indicator.

Get rid of superfluous alt text in “boilerplate” graphics

“Boilerplate” graphics are graphics that are not actual images but are repeating stylistic elements. Boilerplate graphics add style to the page but don’t add actual content and are typically found in templates and repeat throughout the site, as in menu bars. Such graphics which not communicate information to the user should not have any alt text because the alt text will clutter the content of a page, as viewed by the search engines. Such alt text should be deleted from the templates, so that alt attribute is left blank for boilerplate images. It’s a very minor issue, but it’s a super quick fix.

Don’t keyword stuff

Alt text and image filenames are not the place to keyword stuff. As in all SEO, search engines prefer the natural, relevant use of keywords.

Try to use unique alt text

Alt text will be more effective when it is unique; if the same alt text is used for multiple pictures, the alt text loses a lot of value.

Think out image hosting

While using an outside image host can be beneficial in terms of saving bandwidth and helping page load times, note that hosting images on another domain or subdomain comes with possible detriment to SEO. The reason is that the “link juice” of any links, such as hotlinks, going directly to the original image url will not be shared across seperate domains an subdomains. So, if you want the link juice from the 32 links going to rabid_squirrel.jpg to be shared at www.crazy-squirrels.com, host it at www.crazy-squirrels.com/killer-squirrels/photos/rabid_squirrel.jpg not http://static3.crazy-squirrels.com.s3.amazonaws.com/rabid_squirrel.jpg. The SEO benefits of hosting your own images don’t always outweigh the logistics issues, but be aware that there is this tradeoff.

Quality content is king

Images that humans consider to be useful, relevant, and generally awesome are much more likely to rank well in image search engines than crappy images, no matter how much you polish the turd.

Pick your battles

None of the clients I’ve ever worked with have had perfectly search-engine-optimized images. But that doesn’t mean we’ve made SEO-ing the images the top concern for each project. In fact, this is often near the bottom of the list. In most cases, there are more pressing matters at hand, and the relevance and traffic added by optimizing images is often not significant enough to justify spending the time required to get it perfect. In general, you should always go for low-hanging fruit— for example: bulk uploading new alt text when there is none and your cms has that capability. However, a time-suck like renaming every single image filename and re-uploading every image is often not worth the time. For sites whose use of images consists mainly of cliche stock photos and generic photos of people smiling, optimizing the images is not a top priority.

However, there does exist some common scenarios when image optimization becomes quite important. If any of the below bullets applies to you, give image SEO some serious thought. You may want to worry about image SEO when…

  • You are optimizing important SEO landing pages
  • You have image heavy sites or sections of sites, like E-commerce shops or media libraries
  • When imagery is essential to your shtick. For example, you are an interior designer, web designer, landscape architect, photographer, etc…
  • When the images are essential to understanding the content of a page, as in charts, graphs, infographics, or diagrams.
  • When there is significant volume for to be had via image search for a keyphrase.
    • Tip 1: During your keyword research, you’ll note some keywords are obviously used for image search like “printable signs”, “squirrel photos; etc… You may want to go for these with nicely SEO’d quality images.
    • Tip 2: Use Google Analytics to see if you are generating organic search traffic for any image-related keywords and see if the traffic is of notable quality.
  • When you have images that could be potential grade-A link bait. Optimize high-interest, shareable images, like beautiful gut-grabbing photos or memes or funny images. Tip: use inbound link reporting tools (Bing Webmaster Tools, Open Site Explorer, etc…) to see which image urls and image-centric landing pages are attracting links.
  • If you spend a large amount of time and energy optimizing the image to appeal to humans. If this is the case, spend time optimizing it for the engines as well, so more humans can see it. Quality content and SEO are a winning combination.

Do you follow all these steps or ignore your images?

Reid Bandremer

About Reid Bandremer

Reid Bandremer is a Senior Search Project Manager. His background before joining LunaMetrics in 2011 includes eCommerce marketing experience and a pair of business degrees. He is a rabid fan of data, music, and holistic ROI-driven search marketing strategy. Other strengths include SEO metrics, migrations, and searcher segmentation (keyword research 2.0). Contrary to popular theory, Reid is not homeless – he just often stays at the office late because he is obsessed with maximizing the value of clients’ search traffic.

http://www.lunametrics.com/blog/2012/07/17/seo-images/

15 Responses to “SEO for Images”

Marissa says:

While it’s nice that alt tags provide an SEO benefit, they should really only be considered with accessibility in mind, and avoid “keyword stuffing.” For example, I’ve seen all too many times content where you may have an image and a caption, and the caption is then captured in the Alt tag. Perhaps good for SEO, but for someone using a screen reader, may mean the content is actually read aloud twice.

There is an art to picking out an alt tag. Your alt tag should really represent what you would want to be in the place of the image, if the image weren’t there.

Reid Bandremer Reid Bandremer says:

Agreed Marissa. Keywords should be kept in mind when writing alt text and used when applicable and relevant, but keyword stuffing should not take the place of alt text that accurately describes the image.

Mehregan says:

Hi there,
thank you for your time explaining briefly image and seo!

well I have a question here which is not so relevant, I would like to know whether if you use the same image twice in the website it does effect your seo or make it “repetition images” . just to clear you with this I have a website translated in Persian: http://www.pnm.co.ir and English: http://www.pnm.co.ir/eindex.aspx,for example I have the product whiteboards and I like to show it in English and Persian the same image do i need to upload this twice with different name or I can just use the same image in the both parts?
I hope you understand my broken English, as Im new to seo.

thank you for your kind consideration.

Mehregan says:

Hi again!

I have sent a reply but it is not longer here? and I havent get a reply yet?!

all i was asking was if repeating images and use it in the same website twice for example one for english and 1 for persian language just to showcase your product does it matter ?
thank you

Reid Bandremer Reid Bandremer says:

Hi Mehregan,

Sorry, I’m just getting back to you now. Your comment was received at bedtime here before the start of the work week, and I then I had to do a bit of research and client work before giving you a good answer to this tough question.

First, let me give you a disclaimer, and state that I am not very experienced in international SEO; my clients’ user-base is almost exclusively English-speaking. That said, I believe the way you are handling the images will not give you significant problems; it helps that the alt text exists in different languages.

However, I think the English subdirectory of your site may have trouble ranking in English speaking countries, because the top-level-domain (tld) indicates the website is not in English. When possible, it is generally recommended to host content specific to a certain language on the appropriate country-code tld or a generic country-code tld; in this case, http://www.pnm.co.ir/eindex.aspx would be better off as something like http://www.pnm.com.

I think you should research this further, since I am not an expert on international SEO.
Here are some places to start:
http://www.webseoanalytics.com/blog/geotargeting-websites-with-country-code-tlds/
http://www.optify.net/forms/international-seo-starter-guide
http://www.toprankblog.com/2011/09/international-search-basics/
http://support.google.com/webmasters/bin/answer.py?hl=en&answer=66359 (especially the third bullet)

Good luck!

Mehregan says:

Hi there!
my bad! I apologize.
Thank you for your swift reply, at first I was thinking my comment deleted, so I was worry that I include my URL, and it was prohibited.

anyways back to my question:

first of all thank you for your links which helps me a lot.

secondly I would like to know the image file name and alt text , what are the differences? can we use the same alt text same as the image of the file name ?;In this case if I have a product noticeboard with wood frame then image file name is noticeboard-wood-fram.jpg then i use alt text as bulletin-board-mdf-frame

is this correct ? or is this the repetition of names but in UK English and US English ?

lastly is there any different whether you choose your words in US English or UK English ? or can you just mix them in your English site?

thank you in advance, I know you are probably sleeping. Please provide me your facebook and twitter account so that i start to follow.

Reid Bandremer Reid Bandremer says:

Mehregan,

Here’s another link – on the html for images – http://www.w3schools.com/html/html_images.asp
If the filenames accurately describe your images, and use desired keywords when relevant, then (in my opinion) it is ok for the alt text to mostly match the filename, but I would try to replaces hyphens with spaces for the alt text. In manycases, I find the filenames insufficient, so I write unique alt text as is practical.

There is some difference between US and UK dialects.I don’t think I’m the best person to tell you how much difference or what to do about it, but I can say that keyword research will often reveal the best word choice, and that Google’s Adwords keyword tool allows you to view search volume in both the U.S. and U.K. Good luck!

facebook.com/LunaMetrics
@LunaMetrics

Teresa C says:

We would like to create a slideshow of 132 images, each on its own page. The purpose of this content is to appreciate the beauty of images on their own, and we don’t necessarily have any written content to accompany these images. Is it necessary/desirable from a SEO standpoint to create written text to accompany each image? Will we be penalized by the search engines if all we have is 132 images which have each been tagged uniquely, but no other content on the page but the image.

Reid Bandremer Reid Bandremer says:

Strictly speaking, a “penalty” in sEO is when your traffic would actually decrease because you violate Google’s Webmaster Guidelines — you’ll definitely be safe from that sort of penalty. However, you’d certainly be inhibiting a page’s ability to draw additional search engine traffic for your site if the only unique content on the page is the images.

It comes down to a cost/benefit analysis – if you’re creating content solely for SEO, would it get you enough (qualified) traffic to be worth it? and would it not come at the cost of user-experience?

Additionally, 2 things to consider besides copy are: 1) unique Title Tags/headlines, for the pages; 2) putting the whole slideshow on one URL, so you can consolidate the “link juice”. (single URL slide shows also mean users and spiders have less crawling around to do.

A great example of best practices in slide shows is WebMD, as seen here:http://www.webmd.com/pain-management/ss/slideshow-worst-shoes-for-your-feet

Ravi Adepu says:

Helloo..
can I use sitemap for images…?
if I submit the sitemap, google will read alt attribute or caption which I have mention in sitemap.xml file

Reid Bandremer Reid Bandremer says:

Hi Ravi,
You can use xml Sitemaps for images; see http://support.google.com/webmasters/bin/answer.py?hl=en&answer=178636. You can specify the caption in the Sitemap, but not the alt attribute.

Richard Larson says:

Reid,

Thanks for the solid advice, was thinking or developing a list of websites where you can easily hotlink to your images? This might be helpful.

Ryan says:

Reid,

any fear in creating a landing page with all images? basically 2 main medium size images (top/bottom) that include all the promotional content/upsell i need for my product. if the page is key worded correctly and i use the alt text will i be ok?

Reid Bandremer Reid Bandremer says:

Ryan,

Well, a page like this that is very short on visible words is going to be at a disadvantage competing against pages with more text, all other things equal. Whether or not it is a good idea depends on the situation. If the following are true, the liklihood of this being the right page format for you go up:

  • is the competition for the keywords you’re gunning for weak?
  • is the location of the page in the site hieracharcy/architecture such that a lots of internal link equity flows to it?
  • is there a chance other sites would link to this page? Would more words reduce that chance?
  • do you feel that adding words to the page would decrease conversion rates?

If you’re afraid words would distract from the visual elements, you can consider expandable divs. http://moz.com/blog/designing-for-seo

It’s amazing in favor of me to have a web
page, which is useful in support of my experience.

thanks admin