Change desktop chat display size
Zoom’s guide says to sign in to the desktop app, open the profile menu, choose Settings and open Accessibility. Under Chat and video, use the Chat display size percentage. This affects the Chat tab and in-meeting chat according to the cited guide.
Adjust captions separately
In the same accessibility area, Zoom documents a Font size slider for closed captioning, with a preview. Caption reading and chat reading are separate tasks, so choose a comfortable treatment for each rather than copying one size preference automatically.
Use the documented shortcuts in context
Zoom lists Ctrl+Plus and Ctrl+Minus on Windows and Linux, and Command+Plus and Command+Minus on macOS, for chat size during a meeting. Keep the Zoom window in focus. A similar shortcut in a browser can instead change page zoom.
Account for mobile controls
Your questions, answered.
Is chat size the same as caption size?
Zoom documents separate chat-display and caption-size controls.
Where are these desktop controls on the mobile app?
The cited Zoom guide directs mobile users to their device’s font and accessibility settings instead.
Sources & background
Sources supporting this page’s explanations. Practical examples are our editorial suggestions.