An introduction to mobile SEO
March 31, 2015 8:49 am
You’ve probably already heard about the importance of SEO (Search Engine Optimization) in ensuring that your website has a good ranking in search engines, and consequently, so that people can find and visit your site. If people can’t find your site, then your business suffers.
This has been a staple part web publishing for some time, but now that mobile devices have become so widely adopted, there are certain mobile-specific SEO practices that you should pay attention to. In the rest of this article we take a look at some of the dos and don’ts of mobile SEO.
What you need to do will depend, at least in part, on the type of mobile support your site has, that is, how your site was built.
Firstly, note that there is no SEO penalty or preference for one approach to mobile-optimization over another. So whether you’ve gone with a responsive design, adaptive, or RESS approach is not the main issue. All that matters is that the site is mobile-friendly.
A good place to start is with Google’s own Mobile SEO guidelines, published on their developer site.
Signal your mobile setup to search engines
While the specific approach to mobile that you take does not directly impact your SEO, you should indicate to the search engines how your site is set up. This will make it easier for the search engines to understand your website so that it will be ranked correctly.
To indicate that your site is responsive, use the
viewport meta tag e.g.
<meta name="viewport" content="width=device-width, initial-scale=1.0">
This tells the search engines (and browsers) that the webpage will adapt and scale depending on the device screen dimensions.
Dynamic serving is a form of adaptive serving, where different content is delivered on the same URL, depending on the device.
In this approach you should send a
Vary HTTP header to indicate that the content changes for different devices.
This header can be set at the server level, e.g. in an NGINX or Apache configuration file, or at the application level, e.g. using the PHP header function call.
Separate mobile URL
If you have your mobile site on a separate URL, for example, if your desktop version is at http://example.com, your mobile URL might be http://example.mobi, or http://m.example.com. In this case you should use a canonical and alternate link tags to indicate to Google that you have two URLs for related content:
On the desktop site you use the alternate link, to point at the mobile version of the same page, using the
media attribute to specify that its a mobile alternate link:
<link rel="alternate" href="http://m.example.com/kittens" media="only screen and (max-width: 640px)">
On the mobile version, you include the canonical link, to point to the desktop version. Note that you don’t need the
media attribute this time:
<link rel="canonical" href="http://example.com/kittens">
Implicit in this setup, is that you do have equivalent URLs for desktop and mobile sites. We’ll see more of that a little later.
Now that the search engines have an idea about how your site is set up, let’s look at some of the other things you should be doing.
It’s possible to block access to certain files and assets with the use of a robots.txt file. You should not block these assets from search engines differently than you would for any other visitor i.e. search engines should get the same site that real visitors do.
SEO-friendly mobile design
When designing for mobile, keep in mind that mobile devices are generally less powerful and more bandwidth-challenged than their desktop counterparts. Remembering this will help guide design decisions to ensure an SEO-friendly site.
Avoid using Flash. It’s not widely supported on mobile. HTML5 is more widely supported. To be 100% sure you can use device-detection or feature-detection to determine if Flash (or any other technology is supported by a device).
Don’t use popups as they are invasive, and can be difficult to close on mobile.
App download interstitials
Like popups, these pages inviting you to download an app can be irritating and can ruin the user experience, pretty much preventing anything from happening until it is dismissed. Google penalizes pages with app download interstitials, so just don’t do it!
This applies to sites with separate mobile and desktop URLs. When redirecting from desktop to mobile, or mobile to desktop, you should redirect to the equivalent page on the other URL. If you simply redirect to the homepage you are not providing the user with a good experience since they will be getting different, and possibly irrelevant content to what they requested. Google calls this a faulty redirect. Read more about faulty redirects and what you can do about them on mobiForge.
Another potential issue that can arise from using separate URLs, is in providing content on the desktop URL, but showing an error page on the mobile URL. This is clearly not a good experience for your visitors, and it will hurt your rankings. As mentioned earlier, you should have equivalent desktop and mobile pages, and the user should be redirected as appropriate.
While page download speed is important for desktop and mobile alike, it’s particularly important on mobile for pages to download quickly. Mobile users are fickle when it comes to slow pages; and there’s plenty of research to show that mobile users want fast pages.
Google provides its PageSpeed Insights tool to help out here. Feed it a URL and it will analyse your site as both desktop and mobile visitors. It will then give a list of things you need to do to improve. Following its advice will definitely speed up your site, and now that search engines use page speed as a ranking signal, should increase traffic to your site too.
Both Google and Bing offer free webmaster tool services that tie in with their search index, and can be very useful in uncovering potential issues with your site.
SEO, and specifically mobile SEO, are a very important part of any online strategy. Ignore it at your peril. Of course, there is no substitute for having great content in the first place, but even with great content, you need to make sure that you’re accessible and indexable by the major search engines, or your business can suffer.
We outlined some of the basics in this article, but encourage you to read more about mobile SEO on mobiForge. There are many different website configurations and setups, and many different SEO practices that apply in different cases; so it’s worth applying the best SEO practices that suit your specific case, so that you will score well in search engine rankings.