What to show where.
WHAT NOT TO DO
Show different content to different devices.
WHY
People move between devices, search engines see one version, and it creates two things to maintain.
WHAT TO DO INSTEAD
Show the same content, arranged differently.
WHAT MAY DIFFER
Order How much is visible before expanding Image size and crop
WHAT TO BE CAREFUL WITH
Collapsing content on mobile, which reduces how much is read Long pages that become extremely long on narrow screens
WHAT TO DO ABOUT LONG MOBILE PAGES
Break them into sections, with the ability to jump.
WHAT TO ADAPT
Tables, which do not fit narrow screens Multi-column layouts Wide images
WHAT TO PROVIDE FOR TABLES
Stacked presentation, or the essential columns with the rest available.
WHAT TO CHECK
That anything hidden on small screens is genuinely secondary.
WHAT TO TEST
Reading a long page on a phone, end to end.