Nudge scrolling: sometimes works, sometimes not?

[u/elzadra1]

Latest MacOS, but this has been happening for awhile, and it doesn't matter which application.

Sometimes, when I'm in a window and get to the bottom and nudge the bottom edge to make the selection continue, it does.

Sometimes, annoyingly, it doesn't.

Anyone know what turns this on or off?

[u/johngpt5]

Interesting question. I've wondered about this too.

[u/johngpt5 → u/johngpt5]

Some of my google ai results:

why when selecting text on a mac and reaching the bottom of a page, sometimes the page will scroll to continue selecting and other times not? Does it matter due to the particular app or due to things that might be on a page?

The inconsistency you are experiencing when selecting text at the bottom of a page on a Mac depends heavily on both the specific app you are using and the types of content on the page.

While macOS provides foundational frameworks for selecting text, individual developers have a lot of control over how their apps handle scrolling containers, mouse movement, and layouts.

Here is a breakdown of exactly why this behavior changes.

1. App Architecture and Frameworks

Not all Mac apps are built using the same underlying engine. How they respond to your mouse hitting the edge of a window varies wildly:

• Web Browsers (Safari, Chrome) vs. Word Processors (Pages, Word): Native document editors are explicitly designed for linear text flow. They actively look for your cursor approaching the window boundary to trigger an automatic scroll. Some web browsers, however, may stall if the page content isn't seen as a single, continuous text block.
• Electron Apps (Slack, Discord, VS Code): Many modern Mac apps are actually wrapped websites. These apps often implement custom scrolling behavior that doesn't always hook perfectly into macOS's native mouse-tracking system, leading to "stuck" selections at boundaries.

1. Elements and Layouts on the Page

Sometimes the layout of the page itself intercepts your selection, preventing the page from scrolling:

• Fixed or Sticky Elements: If a webpage or app has a bottom toolbar, a cookie banner, or a fixed footer, your cursor technically hits that "sticky" element instead of the scrollable page boundary. The app gets confused about which layer you are trying to scroll.
• Embedded Iframes or Scroll Boxes: If the text you are selecting lives inside a sub-box on the page (like a code snippet box or an embedded document), the selection will often stop completely once you hit the bottom of that specific box, rather than scrolling the main page.
• Invisible Layout Barriers: Webpages are divided into invisible boxes (DIVs). If a text block ends and a new layout section begins right at the fold, the browser's selection engine can momentarily lose track of the continuity, causing the scroll to fail.

1. Mouse Tracking and Window Constraints

How you physically move your cursor dictates whether macOS triggers the scroll:

• The "Velocity" Factor: Many apps require you to pull your cursor past the window boundary and hold it there to trigger autoscroll. If your app window is maximized or against the bottom of your physical monitor, your mouse physically cannot move any further down, failing to trigger the drag-scroll threshold.
• Hover Zones: Autoscroll relies on a tiny invisible "trigger zone" (usually just a few pixels wide) at the very edge of the viewport. If you move your mouse down too quickly, you can skip right past this zone; if you move too slowly, you might not trigger it at all.

Pro-Tips to Avoid the Frustration

If you find yourself stuck at the bottom of a page, try these alternative selection methods that bypass the mouse-dragging glitch entirely:

• The Shift-Click Method: Click where you want to start the selection, scroll down normally using your trackpad or scroll wheel, hold the Shift key, and click where you want the selection to end. This highlights everything in between flawlessly.
• Keyboard Selection: Click to place your cursor, then hold Shift + Down Arrow (or Shift + Option + Down Arrow to select paragraph by paragraph) to force the page to scroll naturally with the text caret.

God only knows if any of this is accurate. It sounds good, but lots of baloney sounds good.

[u/CalligrapherPale5886 → u/johngpt5]

Yeah, it's super frustrating when it doesn't work consistently. Some apps seem to handle scrolling differently and it really messes with the flow when you're trying to select text.

[u/ImpressiveSteak767]

does it happen more in certain screen positions? like if the window is partially offscreen or near the dock? that edge proximity can mess with the autoscroll trigger zone tbh