Pasting a lot of newlines into the prompt input freezes the ui

[quirinecker]

Hello,

We noticed that the UI freezes when a lot of newlines are being pasted into the input field. I understand that the input field is of type div and has the attribute contenteditable = true, which was explained why in issue #285. Although I tested the same input in ChatGPT and it seems to handle a lot of newlines better (still freezes but not as long). To be clear, this is not really that important for us because usually people don't paste that many newlines, and if the line count is below 700, it is not that bad. Below is one video with DeepChat and one with ChatGPT. The input I pasted was just a bunch of . characters separated by new lines for about 1000 lines. Another thing to note is that I only tested this in Firefox and Chrome, and it only appeared in Chrome.

Recording.2026-04-14.102444.1.mp4

Recording.2026-04-14.102252.1.mp4

Thank you for continuously updating this library.

[OvidijusParsiunas]

Hi @quirinecker!
Thankyou for letting me know about the interesting issue!

I did some digging around and found that the problem was caused by document.execCommand?.('insertText', false, text); which was called on paste. The problem is - it caused a DOM re-render on every new line, which obviously caused it to be very slow when inserting many new lines at once.

I have fixed it by using insertHTML which works just as well and only-triggers one DOM re-render.

This is available in deep-chat-dev and deep-chat-react-dev version 9.0.362. Let me know if this helps!

[quirinecker]

Thank you for this quick fix.