How it works
The fold is the lower edge of the currently visible browser area, not a fixed pixel position. Screen size, browser controls, zoom and orientation change it. Prioritise the page title, explanation and primary task without forcing every detail into that area. Content below it can still be valuable and discoverable.
A realistic example
On a mobile glossary page, a tall navigation bar and a large illustration might push the definition off-screen. Reduce unnecessary spacing or place the illustration after the explanation at that breakpoint, while retaining its quality and its role in the article.
What to check
Check the initial view on small and large screens, including landscape and text zoom. Confirm that the page purpose is visible, the first action is usable and the reserved image dimensions prevent jumping. Inspect which asset actually becomes the largest visible element.
Limits and next steps
Do not hide meaningful text or cram controls together to fit an imaginary universal fold. Balance the opening with clear reading flow. Prioritise truly visible media and defer below-screen media when doing so does not delay expected interaction.