TL; DR
Googlebot does not follow links in SVG XML-markup language on web pages.
What are Scalable Vector Graphics (SVG)?
SVG stands for Scalable Vector Graphics and is used to define vector based graphics on the web. SVG is written in an XML markup language and can be edited through a simple text editor. Scalable Vector Graphics do not lose any of their quality if a user zooms in or if the image is resized.
What are SVG links?
A SVG link is an <a xlink:href=””> XML element which is used to link to other URI/URL documents. I have given an example of how this code looks in the image below taken from Mozilla.
To a user, this type of link will act like a HTML <a href=””> link, but to Google these are not the same thing and, in fact, Google doesn’t even follow links in the XML markup.
Crawlers and SVG Links
The SEO team ran a routine SEO crawl on a staging site for a site migration project, using the Screaming Frog crawler. During our analysis we noticed that a number of top level category pages weren’t appearing in the crawl.
Further investigation showed that the pages did have links that a user could interact with by clicking on them, but the crawler wasn’t picking up the links (user agent was set to Googlebot), and so looked at the code instead.
To be 100% honest, our team had never seen a <a xlink: href=””> link before. A quick Google search revealed that it was a SVG XML-markup that was being used to link to important category pages.
Interestingly, the only mention of SVGs on Google’s Official Webmaster help pages is an old post which just says they index SVG documents.
The SVG links were a crawling issue rather than an indexing one, so I thought it best to ask the team at Screaming Frog if their crawler picked up SVG links. I got a quick response from Chris at Screaming Frog, who said that the developers at Screaming Frog would test to see if Googlebot does follow links in SVG markup.
Naturally, I asked if the guys at Screaming Frog would let me know about the outcome of their test. Within a few days they updated me with the results: their tests showed that Googlebot didn’t follow links in SVG markup.
We quickly asked the client and their developers to change these links to HTML <a href””> so that Google could pick them up and follow the links.
The guys at Screaming Frog also gave me some details about their test to share, if anybody fancies running the same test!
Big shout out to the guys at Screaming Frog for not only godlike customer support, but also for being so helpful!
Google Confirms that Googlebot doesn’t follow SVG links
Since asking politely seemed to be getting me answers, I approached John Muller, a Webmaster Trend Analyst at Google, who confirmed that Google doesn’t support links in SVG markup.
@Adoubleagent AFAIK we don’t support links in SVGs, so your tests are probably correct.
— John Mueller (@JohnMu) August 22, 2016
I asked if Google would support these in the future but didn’t get a response (to be fair, he is pretty busy). If I hear back from him, I’ll update this post.
SVG links and SEO
It is also worth noting that if pages are not linked to properly within the website architecture, this may impact on organic search performance.
Not only does Google use internal linking to help understand your website pages better through internal anchor text, but the number of internal links to a page can indicate how important it is. Internal links are also important as link power is passed down the site hierarchy, from the homepage all the way to deeper level pages.
If Google cannot see SVG links that users are clicking on, then pages like E, D and G in the image below won’t gain the SEO benefits from internal linking!
Don’t use SVG links
The bottom line is that you shouldn’t place links in SVG markup if you want Google to crawl, index and rank your content. Screaming Frog’s test and the confirmation from John Mueller is strong evidence for SEO consultants (in my opinion) to advise clients against this type of linking method.