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Xcode 16.3 Doesn't Remember Preview Pane Width

It seems like, by default, the preview pane tries to align to 50% of the editor pane's width.

I prefer to shrink the preview pane to around ~30% of the screen so I have more space for code. This used to work fine—at least until I restarted Xcode. I never understood why the setting wouldn’t persist across sessions, but fine, that was a tradeoff I was willing to live with.

However, with Xcode 16.3, it seems like Xcode forgets the manually adjusted preview pane width as soon as I switch to a different file. This has definitely impacted my productivity, as I now find myself readjusting the pane size dozens of times in a single session.

Am I holding it wrong? Is anyone else experiencing this?

And while we’re at it—why not make this a persistent setting so everyone can tweak the width to their liking?

Answered by B347 in 837371022

ah...fixed! :-}

with latest Xcode (28 April 2025) Version 16.4 beta (16F1t)

The size of the preview pane is kept between editor/file changes and is not reset to a default value.

Edit: It seems that when switching between different SwiftUI view files, the previously adjusted width of the preview pane is retained. However, when switching between a non-SwiftUI file (or a file with preview disabled) and a SwiftUI file with preview enabled, the width is reset.

Accepted Answer

Hi,

Sorry to hear you are having problems while using previews. You are hitting a known regression that causes the canvas to revert back to the default split rather than restore the previously manually set split configuration.

Unfortunately I don't have any workarounds to offer you at this time.

Yes, I get this too. It's annoying on my desktop and extremely frustrating on my laptop.

If there is no workaround at the moment can we at least be assured it will be fixed soon?

I have a similar issue with Xcode 16.3. Readjusting the preview pane every time is not okay. I switched back to Xcode 16.2, which we can download separately from Apple or Xcodes app.

+1 I can also confirm the malfunction here. That annoys me too. It seems that 16.3 is not really a good value (so many issues).

+1 You put it well, it's very frustrating. I hope this gets fixed soon.

A temporary workaround that I'm using is that I open two windows: one for files with previews and another for non UI files.

Dear Apple, the canvas don't have to take this much horizontal space; we always resize to fit just the device and give the rest of the space to the editor.

How does this get through testing?

It's basic functionality.

Preview is almost unusable in this release. It either takes ages to compile the simplest of views, or I get "Failed to launch app in reasonable time", on trivial "Hello World" views.

The problem is exacerbated by the small resize area. On large screens you have to inch the mouse over the area to hit on the resizable zone so you can resize the window.

ah...fixed! :-}

with latest Xcode (28 April 2025) Version 16.4 beta (16F1t)

The size of the preview pane is kept between editor/file changes and is not reset to a default value.

Yes this should be fixed now in 16.4. Please let us know if you run into it again!

Xcode 16.3 Doesn't Remember Preview Pane Width
 
 
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