Google search engine algorithm will increase the weighting for mobile-friendliness for search rankings starting April 21 next. Websites offering below-par mobile optimization will experience a drop in search traffic from mobile sources. Read on to learn more about the upcoming algorithm update and the mobile-friendly requirements.

What do we know about the mobile-friendly algorithm change?

Google has been promoting mobile-friendly best practices for a few years. Plans to introduce ranking changes to improve the mobile search experience were unveiled back in 2013 along with a list of common optimization mistakes and mobile-friendly guidelines for developers.

In November 2014, Google rolled out mobile-friendly tags that appeared in mobile search results highlighting websites optimized for smartphones. A mobile-friendly test site was also made available so that developers could test their websites against Google’s requirements.

Posted on Google’s Webmaster Central Blog, the latest announcement stated that ‘mobile-friendliness’ will be widely expanded as a ranking signal starting from April 21. According to Google, this change will be more significant for mobile search than Penguin and Panda were for desktop search.

Here are key aspects of the approaching algorithm update.

1. Only mobile search will be affected

Google’s announcement states that the algorithm update will affect mobile search. There’s no mention of desktop search, and therefore we assume that websites failing to properly address mobile audience might still rank high in desktop searches.

2. The algorithm will run real-time

Pages not optimized for mobile will improve their ranking positions immediately after becoming mobile-friendly.

3. The algorithm will run on a page-by-page basis

Every page on your website will be individually analysed in terms of mobile optimization. A single faulty page won’t harm the entire website’s ranking.

How to be mobile friendly -- a rough guide

Given the growing share of mobile traffic, the approaching update to Google’s algorithm is relevant to every website owner. Businesses that so far haven't focused much on addressing mobile audience must now rethink their online strategy so that they don’t get punished in the SERPs.

Here’s a rough guide to becoming ‘mobile-friendly’ according to Google.

1. Different approaches to addressing mobile users

According to Google’s guidelines for web developers, there are three methods for coming up with mobile optimized content.

• Responsive Web Design
• Dynamic Serving
• Separate URLs

RWD means that content rearranges itself on-the-fly, client-side. The same website code is executed on every device. Dynamic serving is a setup where different devices receive different website code but the website URL stays the same. In the third option, different website code and different URLs (such as m. or .mobi) are sent to different devices.

Dynamic Serving and Separate URLs (often referred to as Adaptive Web Design, or content adaptation) both require User Agent-based server-side device detection, such as DeviceAtlas, to identify the requesting device and send the appropriate website code. Learn more on content adaptation from our free paper.

2. The website must be accessible to Googlebot

JavaScript, CSS and image files should be fully accessible to Googlebot so that the bot can see the website like an average user. Using Google’s mobile-friendly test you can check out if the website is available for crawling.

3. No faulty redirects and irrelevant cross-links

A common smartphone optimization mistake is using URLs which don’t open on mobile but instead redirect mobile visitors to default URLs or serve 404 error pages instead of redirecting users to equivalent mobile pages.

Google also indicates that, if using a separate URL setup, you need to make sure that links to desktop versions of pages point to their correct equivalent pages, and not to a default URL (e.g. main page).

4. No desktop-specific content

Google recommends avoiding software that may not work on mobile devices, like Flash. Webmasters should consider using HTML5 instead. It is also recommended to use large fonts and tap-friendly links.

We also think this includes avoiding large images and videos, OS-specific downloads, resource-hungry scripts, complicated forms, etc. which might work on smartphones but impeding user experience. Using Dynamic Serving or Separate URLs you ensure that each bucket of users receives a 100% optimized experience with no desktop-specific components.

5. Fast loading times

Mobile optimization best practices include optimizing website speed, given that users expect websites to work on their smartphones as fast as they do on desktop computers.

While RWD sites often struggle to deliver fast performance on mobile devices, we recommend applying content adaptation (Dynamic Serving, RESS, or Separate URLs) which gives you more flexibility adjusting the website speed and page weight.