No loss of content or functionality should occur on mobile devices at 320 pixels width. No horizontal scrolling should be necessary unless content cannot be resized effectively.

What you need know

• This success criterion requires that your content reflow on smaller screens without negatively impacting the user experience.
• If a website is fully responsive, this success criteria is likely already met. However, the responsiveness of your content should still be evaluated.

What you need to do

• Ensure your CSS enables your website content to be zoomed up to 400% without causing loss of information or function and that users have to scroll to see it.

Reference

Read the full explanation of success criterion 1.4.10 on W3.org.

Related Resource

Check out “Reflow” from the DAISY Consortium’s Accessible Publishing Knowledge Base for more information about this success criterion.