I can't has cheezburger

macOS Sonoma has had a bug since its release. I’ve been dutifully reporting the bug to Apple and the bug reports have gone ignored for months now, so it’s time to run to the press (okay, I’m being generous calling this the press) and see if other people see the same thing. (Also, I reached out to Apple Support to have them escalate to engineering last week since support teams tend to do a better job of following up)

Generally, Mac apps handle text input just fine, even when you’re typing very fast (this is an AppleScript typing keystrokes with a 0.01 second delay between them:

Now, let’s try typing text into the Messages app:

Initially, it looks okay! But shortly Messages stops responding to individual keystrokes and has noticeable delays between them.

If you want to really see issues, try having an image in the text field:

As you can see here, something is seriously wrong. The text input is heavily buffering, and this is while using a much shorter snippet of text; the one I was using in the first two examples basically locked up the Messages app.

I have two Macs running Sonoma, one Intel and one Apple Silicon; the issue happens on both. It’s not specific to my iCloud account. I can log in as a different user with no apps installed and still reproduce the issue. A friend was able to reproduce the issue too.

The Messages app is clearly under some load when it lags like this; you can see its CPU spike and sometimes the app will even hang when this is happening.

If you work for Apple and know an engineer on the Messages team, see if you can get this issue on their radar.

If you don’t work for Apple but you use Messages on your Mac, I apologize if you were previously living in ignorant bliss not knowing about this, but now you can’t un-see it. In that case, now your best bet is to spread this message far and wide in hopes that we can make enough noise that Apple will notice.

The good news is this performance regression seems to be isolated to something in the Messages app itself. Other Mac apps, and even other Catalyst Mac apps seem unaffected.