Web browsers keep expanding on MacBook Air M1

Since you’re using a 2020 MacBook Air M1 running macOS Tahoe, I’d start by checking a few Mac settings before trying anything more drastic.

1. Check Accessibility Zoom

Go to Apple menu  → System Settings → Accessibility → Zoom.

If you don’t use Zoom, temporarily turn off the options for keyboard shortcuts, trackpad gestures and scroll gestures with modifier keys. One of these could be triggering the enlargement.

2. Check what’s actually expanding

If the entire browser window grows, check System Settings → Desktop & Dock → Windows for window tiling and arranging options. Also notice whether it happens when you drag a window or wake your Mac from sleep.

3. If the webpage content gets bigger

In each browser, press Command (⌘) + 0 to reset the page zoom.

You can also check:

• Safari: Settings → Websites → Page Zoom.

• Chrome: Settings → Appearance → Page zoom.

• Firefox: Settings → General → Zoom settings, depending on your version.

4. Check for an accidental trigger

Restart your Mac and test one browser at a time. A stuck keyboard key or an unintended trackpad gesture could explain why all three browsers are affected.

Before reinstalling anything, though, I’d like to clarify one thing:

When you say the browsers keep “expanding,” do you mean:

A. The browser window grows to fill the screen.

B. The text and pictures on webpages get bigger.

C. The entire screen zooms in, so you can see only part of it.

D. The browser windows change size or position by themselves.

Knowing which of these describes your problem will help narrow down the cause without sending you through the same fixes you’ve already tried.

I use the scroll gesture with a modifier: Zoom in on your Mac screen - Apple Support

Is that happening here accidentally?

Unless it’s the whole window going full-screen, and that can be triggered by the ^⌘F shortcut.

Since this is happening in Chrome, Firefox, Safari, and now Notes, the cause may be a macOS setting or keyboard shortcut rather than the browsers themselves.

Could you clarify what happens when the expansion occurs? 

Does the app enter Full Screen (hiding the menu bar and Dock), does the window enlarge to fill the screen while they remain visible, or does the screen or text become magnified? 

Does it happen randomly or when using the keyboard or trackpad?

One setting worth checking is System Settings >> Accessibility >> Zoom, where you can review keyboard and trackpad zoom options. 

These can magnify the screen independently of a browser's own zoom settings.

Wendysusanjones wrote:

MacBook Air M1, 2020

Chip: Apple M1 MacIntosh HD

MAC - Tahoe 26.6.2

Hi. I have Chrome, Firefox and Safari as browsers. They all keep expanding and it's driving me up the wall. I've looked at posts regarding this and followed instrucions to the T but nothing seems to work.

Suggestions? Thanks.

W. Jones, Vancouver

Why don't you try explaining what you mean by "expanding" and tell us exactly what "instructions" you followed?

You haven't provided enough information to know what's wrong.

Thanks. I did this but it didn't work. It just did it in my Notes program for the first time.