Note: The SharePoint Online Public Website information in this article applies only if your organization purchased Office 365 prior to March 9, 2015. Customers who currently use this feature will continue to have access to the feature for a minimum of two years after the changeover date of March 9, 2015. New customers who subscribed to Office 365 after the changeover date don't have access to this feature. Moving forward, Office 365 customers have access to industry-leading third-party offerings that enable them to have a public website that provides a complete online solution and presence. For more information about this change, see Information about changes to the SharePoint Online Public Website feature in Office 365.
By default, your Office 365 public website is set up to display the same way on mobile devices as on a full-sized monitor, so phone and tablet users may have to do a lot of scrolling. However, you can change this with a pre-built mobile master page. Master pages provide a common navigation structure for all pages on your site. You can select a default master page and a master page to be used just when users view the site from a mobile device.
As soon as you change the mobile master page, people using mobile browsers will get a view that works for smaller screens:
You’ll see two major differences: navigation is done as a drop-down list, and lines wrap to fit on the smaller screen.
The mobile master page is automatically applied to all pages in your website, so there’s no need to republish. It works with any theme. There is no separate URL: when people go to any page using a larger screen, they see one view of the site, and when people use a small screen, they see the new mobile view.
Add a mobile master page
Go to Sites > Public Site, and then in your public website, click Settings .
Select Site settings.
In the Look and Feel section, select Master page.
In the Any Mobile Device box, select any of the mobile master pages:
Note: The four default mobile master pages provide the same layout, so you can use any of them.
Click Home to return to the home page of your site.
To preview your page as it would look on a device, on the Page menu, select Preview, and then select Any Mobile Device.
Important: If your browser blocks pop-ups, you’ll see a message “Internet Explorer blocked a pop-up.” Click Allow Once, click Retry, and then the preview opens in a new window.
Drag a corner of the preview window in to make the preview browser window smaller, so it matches what you see on a mobile phone or tablet.
Need to customize the mobile layout?
If you create a new master page for your website, you may also want to create a new master page for the mobile view. For more information about creating master pages, see Use Design Manager with your Public Website in Office 365.
To learn more about customizing your website and pages, see Public Website help for Office 365.