Do you still get the pages in mobile mode if you switch to Full Screen mode (F11) in case the current screen dimensions are too small? This also can happen if you zoom the page or use a large font size.

Can you attach a screenshot that includes the user interface?

• https://support.mozilla.org/en-US/kb/how-do-i-create-screenshot-my-problem
• use a compressed image type like PNG or JPG to save the screenshot

I get the desktop view when I toggle fullscreen, but I did not have to do that even a few days ago. I tried zooming in and out and it didn't change the layout of the pages I used to test, and also no matter what I did, my changes reverted when I closed the browser window, even if the library was still up.

I've taken a screenshot of the page I've been using as a demonstration with tech friends. Used the microsoft method because that guaranteed it would show the whole window, and as I'm totally blind, I couldn't ensure I captured the right thing otherwise.

Unfortunately the image if completely white color with dimensions: 1,152px × 1,027px. Maybe try to increase the width of the Firefox window a bit to see if that has effect as a lot of webpages automatically adjust their layout to the available screen estate and might expect a width over 1200.

You may have accidentally zoomed webpage(s). Reset the page zoom on pages that cause problems.

• View -> Zoom -> Reset (Ctrl+0/Command+0 (zero))

• https://support.mozilla.org/en-US/kb/font-size-and-zoom-increase-size-of-web-pages

I tried that and it didn't work! I've tried messing with Zoom and it just does not work, and this is on multiple pages! It's on the page I tried to screenshot, my Tumblr dashboard, another website I use all the time...

And it's stuck doing this by default! It resets back to this behaviour whenever I close the browser window!

Here's a screenshot of the page taken within Firefox. I don't think pasting into Paint worked very well...

The above screenshot is not the same page as the screenshot I tried to do earlier, but I couldn't edit the above post to correct it because I don't know how to do that on this forum, so I'm posting a reply to correct it.

You can find "Edit this question" under the sidebar "Question Tools" menu (you may have to scroll to the top). For a reply, "Edit this post" is in the three-dot menu next to a reply.

You get this layout when the screen isn't wide enough, for this forum the switch happens with a width above 1024px. Do you know how to adjust the width of the Firefox window? As a quick test you can zoom out the page one or more steps to simulate a larger screen estate.

I noticed that the current Firefox release show a popup for a short time with the screen dimensions in the top right corner when I zoom or change the dimensions, but I do not know whether this is exposed/handled by a screen reader.

Trix, did you try toggling Responsive Design Mode? On Windows you can press Ctrl + Shift + M. For alternative methods see the "Toggling Responsive Design Mode" section here: https://firefox-source-docs.mozilla.org/devtools-user/responsive_design_mode/

Trix, did you try toggling Responsive Design Mode? On Windows you can press Ctrl + Shift + M. For alternative methods see the "Toggling Responsive Design Mode" section here: https://firefox-source-docs.mozilla.org/devtools-user/responsive_design_mode/

I did, but I couldn't find a way to restore what was lost in any of the menus that command opened up. And my tech friend said there should be an X option to switch back to desktop and there isn't one, which he said means the browser thinks it's on a mobile device.

You can find "Edit this question" under the sidebar "Question Tools" menu (you may have to scroll to the top). For a reply, "Edit this post" is in the three-dot menu next to a reply.

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You get this layout when the screen isn't wide enough, for this forum the switch happens with a width above 1024px. Do you know how to adjust the width of the Firefox window? As a quick test you can zoom out the page one or more steps to simulate a larger screen estate.

I noticed that the current Firefox release show a popup for a short time with the screen dimensions in the top right corner when I zoom or change the dimensions, but I do not know whether this is exposed/handled by a screen reader.

I think I did see that popup earlier, but I have to be quick to see it before it disappears.

I was able to get the desktop layout back after zooming out three steps. I don't know how to permanently change the width of the window though. Returning to the original size with ctrl+0 restores the behaviour I do not want.

Trix, does anything in the "Device selection" section of that link help?

That section also talks of how it changes your User-Agent header, so perhaps whether this is set correctly might be worth looking at next, if nothing else helps.

Trix, does anything in the "Device selection" section of that link help? That section also talks of how it changes your User-Agent header, so perhaps whether this is set correctly might be worth looking at next, if nothing else helps.

None of the devices listed are relevant—I'm on a PC with a monitor. I don't want to change my browser to something even more messed up/optimised for a mobile device I'm not on...

There is a desktop site option where you can switch from mobile to desktop in the Firefox browser.

There is a desktop site option where you can switch from mobile to desktop in the Firefox browser.

But will it work if the window is still too narrow? Zooming out worked once I'd done it three times.

Trix, what is your User Agent string?

To see this go to Help Menu > More Troubleshooting Information, then find User Agent in the table under the heading "Application Basics" (this may be a level 2 heading for your screen reader).

What I am considering is the possibility that Firefox has changed the User Agent string that it reports, and so now websites think that this is a different browser / OS / device than it is.

Trix, what is your User Agent string? To see this go to Help Menu > More Troubleshooting Information, then find User Agent in the table under the heading "Application Basics" (this may be a level 2 heading for your screen reader). What I am considering is the possibility that Firefox has changed the User Agent string that it reports, and so now websites think that this is a different browser / OS / device than it is.

My User Agent string is: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:130.0) Gecko/20100101 Firefox/130.0

I'm to understand this is the one expected for Windows 10, and I do use Windows 11 on this PC, but my previous computer, from which this profile was most recently copied, was on Windows 10. Regardless, this is still a Windows UA.

The Zooming adjustments have stuck around, so at least those won't break. One does still wonder why the default the screen reverts to with ctrl+0 is so small we end up in mobile view.

There are two ways to change the screen dimensions, one is to drag the border with the mouse (hold the left mouse button), another is to use Resize in the "Alt+Space" System menu.

If you do not keep the dimensions when you close and restart Firefox then there might be a problem with xulstore.json in the Firefox profile folder.

In that case, try to rename/remove xulstore.json in the Firefox profile folder with Firefox closed.

You can use the button in "Help -> More Troubleshooting Information" (about:support) to go to the current Firefox profile folder or use the about:profiles page (Root directory).

• Help -> More Troubleshooting Information -> Profile Folder/Directory:
  Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data