Recently the Webmaster Central blog stated that on April 21st, Google will be expanding its use of 'mobile friendliness' as a ranking signal. Google have directed webmasters to their Mobile Friendly Test tool and many have also been using PageSpeed Insights to drill down further into how their site might perform on a slower mobile-network connection (when compared with fibreoptic cable, etc).

Some people have been asking whether mobile friendly signals and site speed will also be important for Google's tablet results. Information on Google's tablet-specific results format (when set against mobile or desktop) seems to have arisen in 2011, first on Search Engine Land.

Since tablets have their own uniquely formatted Google search results, will sites which rank negatively on mobile (due to poor site speed or a lack of mobile-friendly design) also perform poorly on tablets?

There's an awful lot to get one's head around here. The short answer is: possibly

Tablets don't usually have a sim-card unlike phones, which means their internet connection isn't usually sent through a 3g / 4g connection (though this is possible).

Most often tablets receive their signal via wi-fi broadband and thus (generally speaking) share desktop rendering speeds rather than mobile rendering speeds. I can't be certain that Google have factored this, but I'm pretty sure that they would have.

It's likely that incredibly low page-speed scores will negatively affect even the desktop site's rankings to some degree. Unless page-load speeds are extremely negative however; I can't see the same level of penalty being handed out on tablet results as would be dealt on mobile (phone) results.

As we all know, there are few ways to build mobile sites. You can use separate mobile sites ('mobile.', 'm.', '/mobile' etc.) or you can use responsive design (same HTML / PHP files, different StyleSheets are served depending on device).

What you may not know is that there are several different way to trigger a separate mobile site as the user loads the specified page. In the case of responsive design; there are many ways to trigger the mobile StyleSheet (CSS) though the actual core files (PHP, HTML, ASP etc.) are the same.

Usually JavaScript is used to switch the StyleSheets for responsive design:

In the above example, mobile StyleSheets are initiated for any resolution with a width below 1,085 pixels (around the max width of the Samsung Galaxy S4).

User-agents may also be used to initiate the switch. For example: "Dolphin" is a popular android browser, so if the Dolphin user agent is detected - the mobile StyleSheet should be applied. The user's OS (Operating System) can also be detected using JavaScript and may be used to perform the mobile-site / StyleSheet switch. If an Android or iOS operating system is detected, that information may be used to perform the switch effectively.

Well; in order to determine whether Google will consider a website non-tablet friendly, we need to know how the website boots separately for mobile devices and tablets.

• If the specified website assigns a mobile browsing experience via pixel-width (tablets have a much larger width than mobile phones), it's likely that the desktop site will deploy for tablets. This means Google would likely apply the desktop PageSpeed score to the website from within tablet-based search rankings. This is especially true since tablets usually share desktop connection speeds, rather than mobile rendering speeds. Even if there's a distinct difference; tablets will be much closer to desktop rendering speeds than to mobile rendering speeds.

• If the website in question re-organises itself via user-agent or OS, it's likely that the mobile site will deploy on a tablet (which will use the same 'apps' and therefore 'user-agents' as mobile). This would make the mobile PageSpeed score more likely to apply for tablet-based search results. This would also mean that mobile ranking factors would be much more likely to play a part in this hypothetical website's tablet rankings.

• If the website in question uses JavaScript to form a third style (just for tablets); it's true that the PageSpeed Insights tool does not (currently) provide information for your tablet-specific responsive design and thus we don't have a lot of information to go on. I'd like to think that Google would reward designers and webmasters who specifically tailored their site to not just the mobile but also the tablet browsing experience. Anything we can divine in this area is fairly spurious.

If you want to have a shot at answering that question, what you really need to do next is to work out how your mobile site deploys and which version of the site deploys on a tablet:

• Get a tablet, a mobile phone and a desktop computer. Load your site in each. Are mobile and tablet the same design? Are mobile and tablet the same as desktop?

• You may need to ask your development team for the script that controls mobile deployment in order to be 100% certain

• When you have worked out how the site deploys on a tablet, you will be able to guess with a degree of accuracy which ranking factors Google should logically deploy for your website.

Note that: Even if the desktop site is used for tablets (and thus the desktop ranking factors 'should' apply) - there may be a slight penalty since a bespoke tablet design has not been produced. Google will want to reward designers who have specifically considered tablets and written StyleSheets just for those devices.