Is your feature request related to a problem? Please describe.
Well whenever I open chat and it's been a while the chat shows all the way to the top taking up half the screen. I know there's a "maximum chat messages" thing but wasn't sure if that meant all messages or chat size.

Describe the solution you'd like
An option to adjust chat size visually. Like so it doesn't take up half your screen

Describe alternatives you've considered
Blank...

Additional context
Pretty much said it all I think

thanks. Didn't know about that

if you're talking about the chat window height, have you tried the minecraft options -> chat settings -> focused chat height?