Recently, I was checking through Google Webmaster Tools for the sites that I manage and I noticed that a PageSpeed Insights suggestion was flagged up for my site, telling me that I need to set the Viewport for the site to be rendered correctly on mobile devices.

Configure the viewport

Your page does not have a viewport specified. This causes mobile devices to render your page as it would appear on a desktop browser, scaling it down to fit on a mobile screen. Configure a viewport to allow your page to render properly on all devices.

Now, I had the viewport tag already in the <head> of my site, in format:

    <meta name="viewport" content="width=device-width, initial-scale=1">

However, the Google documentation on this showed the name attribute for the tag being set with no quotes, like so:

    <meta name=viewport content="width=device-width, initial-scale=1">

Technically, I know this is no different than the <meta> tag I was already using, but I decided to give it a go and it worked!