SEO Question: Is link juice passed via the HTML head section and/or jQuery plugins?

Image from SXC.hu

This weeks SEO question is:

When you include links to other domains in your head (<head></head>) section in order to get JavaScript libraries, etc., do you bleed off a certain amount of “link juice” to those domains or does Google somehow treat the section differently?

Another good example is using something like the jQuery Flickr Gallery, which goes to Flickr for a photoset and then generates (on the fly) a whole series of links to flickr.com to get the images you want to display.

Since all my sites do a php include of the header for each page, if links in the header are counted, I suspect that all links in that header are recognized as backlinks to those sites – for each of my pages. If I am getting more than one script per site though (i.e. having more than one link to a site in the header), I think it would only be counted by Google as a single backlink.

As far as the Flickr Gallery goes, I also think that all those links back to flickr.com would only be counted as a single link by Google. What do you think? Then the next obvious question is (if my assumption is correct) is it enough ‘link juice’ to even worry about?

Great question, lets break this down into two parts:

Part 1 – the <head> section

W3Schools,com defines the head section as follows:

“The head element is a container for all the head elements. Elements inside <head> can include scripts, instruct the browser where to find style sheets, provide meta information, and more. The following tags can be added to the head section: <title>, <base>, <link>, <meta>, <script>, and <style>.”

From my experience, anything within the head section is technically classed as an element that either defines a part of the web page or instructs the browser to do a function. So linking to a jQuery files and the like within the head section of the page wouldn’t pass link juice.

The search engine spiders that crawl web pages would see this section as irrelevant to standard content and links. If it was the case, surely they would be classed as hidden links thus resulting in a penalty.

Part 2 – WordPress plugins, jQuery and the like

Now this is an interesting one and we’ll use the jQuery Flickr Gallery as the primary example. Once the plugin has been installed and functioning on the site, the HTML code links to Flickr so the larger image can be displayed, typically through a Lightbox function, which technically is a link.

But, to pull the smaller graphic through (aka thumbnail image) which you click on to see the larger version, this is also being pulled from Flickr or its using a jQuery element to resize the original – all a bit complicated but theoretically it’s all interlinking between Flickr so its not classed as a typical backlink (or, works in a similar fashion to an iFrame).

I’ve researched this further and looked at some Flickr Galleries and did some backlink analysis. I was unable to find any links from the site with the gallery. I also checked Google image rankings for any further evidence and this proved the theory further.

So to answer the question, links within the head section or through plugins don’t pass any link juice. I’m very open to any comments around this and any further evidence.

This post was written by Dave Cain, published on 16th January 2012 and filed under On-Page, Questions, SEO. Dave is a digital marketer specialising in SEO and PPC, and can be followed on Twitter, Facebook, LinkedIn and Google+. You can also subscribe to his blog feed.

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One Response to “SEO Question: Is link juice passed via the HTML head section and/or jQuery plugins?”

  1. Dave, Great information!

    This means that, when doing a gallery, etc. there is no “SEO tradeoff” between storing the large images on your own server vs. pulling them from Flickr.

    The only tradeoffs would be any difference in coding and performance.

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