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Mobile friendly testing tools are growing up

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With the announcement of its new Mobile Checker project by the W3C last week, two of the web’s oldest mobile friendly checkers have recently been upgraded. The other is Afilias’ mobiReady tool which predates even the W3C tool. In both cases, a major rewrite has transformed each tool.

Related: Performance testing: what is it and what tools you should use

What does a mobile friendly checker do?

A mobile checker performs a suite of tests on a web page to determine whether it is mobile-friendly. That is, whether or not it will display well on a mobile device, and if it will load in a timely manner. That last bit’s important: the slow network connection is the bane of the mobile web surfer, and a serious impediment to a good mobile web browsing user-experience. The best way to deal with slow network connections is to reduce the size of the page and number of network connections using techniques such as

  • reducing, minifying and aggregating HTML markup, CSS, and JavaScript where possible
  • optimal compressing of image assets
  • employing optimal caching

These things are vital since a page cannot be considered mobile-friendly if it doesn’t load quickly, so any mobile friendly checker worth its salt must check these things. Google has an unfortunately named ‘Mobile friendly tester’ tool, but which has been shown to mark huge slow pages as mobile friendly. It’s good for telling you if your web page will fit onto a phone’s screen, but not whether it will be a good mobile experience. Google has a different tool called PageSpeed Insights which can help optimize performance.

Of course, these are not the only things to consider when checking if a page is mobile-friendly. There are plenty of other things to be checked too, such as detecting whether the page will fit on a small screen without panning and zooming, and whether it uses components that will work on mobile devices, such as the use of plugins such as Flash.

mobiReady mobile friendly checker


The mobiReady tool was originally launched back in 2006, and tested for a most of the items mentioned above. You gave it a URL and it checked for the W3C Mobile Web Best Practices MWBP and some extra tests not covered by the MWBP. It then rated how likely the webpage was to display on a mobile device. It masqueraded as the Default Device Context, which was a baseline (theoretical) device, and had options for testing separately as a variety of then popular devices.

Mobile friendliness on multiple devices

Seven years after the launch of the iPhone, it needed a lick of paint on the outside and a tune-up on the inside. Mobile devices have become a lot more capable in the intervening years, the have bigger screens, more RAM and faster processors, so the types and size of web components that they can display has changed quite a bit.

Mobile friendly tests

The new version tests pages as a number of different devices at the same time, giving a more complete picture of how well a page will perform across the spectrum of devices that visit websites today, and shows how the webpage breaks down in terms of images, HTML, and JavaScript.

W3C Mobile Checker


The original W3C MobileOK Checker tool followed a little after the mobiReady tool, and performed a similar job. Its tests were based only on the Mobile Web Best Practices. It was due to be retired in 2014 for reasons that it had become less relevant to more modern devices, though it is still live at [] at the time of writing. The new W3C Mobile Checker can be considered its next incarnation. It’s had a complete rewrite, moving from Java to JavaScript/Node.js, and with updated tests to reflect the maturing capabilities of mobile devices.

W3C mobile friendly checker

Unlike the mobiReady tool it only gives a single device view at a time, but you can choose the device on the first page. And like the mobiReady tool, it performs a number of tests, and indicates where things might need fixing or improving.

The updates to both of these tools are overdue and welcome, making it easier for site owners and developers to guage a site’s mobile-friendliness and optimize it for all visitors. Whichever tool you decide to use, be sure to test your pages! Mobile browsing has overtaken desktop browsing, so if you’re not checking if your pages are mobile-friendly you could be missing out on visitors and traffic.

Main image: Tim Sheerman-Chase