According to one of our multi-line fields - 32,767 characters
@Ollie Guan beat me to this - but he's right, ours is limited to 32,767 (I assume this was a default).
You can modify the limit as a Jira Admin:
Hi everyone 👋, I really like the format of the webinar opportunities summary that @Jimmy Seddon posts monthly on the Welcome Centre group. It's a great place to go to check that you didn...
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events