Browser issue Cutting and pasting large chunks of text causes the browser to crash/lag


Well-known member
Not sure if it's a browser issue or the editor itself, but It shouldn't be like this. FYI, I'm on Retina Macbook Pro (15"), so my laptop isn't the issue (probably).
Cutting and pasting large chunks of data creates a lag in my Chrome browser, and after it gets "too big", it crashes.

Along the entire video, I'm pasting and cutting right away, but when you see my mouse goes "crazy", it means that my browser doesn't respond and I can't do anything about that. It's beter to watch that in 720p:


Luke F

Well-known member
Confirmed in Chrome on Windows, it's significantly slower than Firefox

Though to be honest this is arguably just a browser issue


Well-known member
I just tried it again, no problems when I try it. I suggest you try another computer to verify it's not something to do with your computer.

Adam Howard

Well-known member
I can not confirm this. I used a full Wikipedia page. Copied the whole page from top to bottom, including all the reference links, all the way down to the foot where it reads
  • Privacy policy
  • About Wikipedia
  • Disclaimers
  • Contact Wikipedia
  • Mobile view
Pasted it into the editor, then typed some more. About 2 paragraphs of my own. I then selected all, cut, copy, and pasted.

I used this page (movies usually have lots of info on them)

Used Firefox 22 on Windows 8 Pro.... Could not confirm. Sorry.

But I could confirm that there was a moment where my browser didn't want to respond. This isn't something that happens in the TinyMCE editor. But it didn't keep repeating like yours did. Once it was pasted into the window, that was it.


XenForo developer
Staff member
Ironically, in my testing, doing what we do with the paste events actually speeds it up - from 8-9 seconds to 2-3.

However, in general, there's very little we can do with this in the general case. The speed issues actually come from the browser laying out all of the new DOM elements.