Weekly Emacs tip #23 — Resizing the display font in Emacs

Something that may come up when sharing your Emacs screen in a video call: how to increase or decrease the font size? This turns out to be quite easy with the mouse scroll wheel:

• C-scroll will resize the font of the current buffer
• C-M-scroll will resize the font for all buffers.

If you don’t like to use the mouse, you can use:

• C-x C-= or C-x C-+: increase the buffer font size
• C-x C--: decrease the buffer font size
• C-x C-0: reset the buffer font to the default size

Note that after pressing the initial key combo, a message in the modeline will tell you: Use +, =, -, 0, C-+, C-=, C--, C-0 for further adjustment, so no additional C-x is needed (until you hit a key not listed there). The function that gets called for each of these key combos is text-scale-adjust, which adjusts itself to do what you meant depending on the last part (the +, -, or 0).

To change the font size for all buffers using the keyboard, use:

• C-x C-M-= to increase
• C-x C-M-- to decrease
• C-x C-M-0 to reset to the default.

Here to, you’ll see a similar message informing you that you don’t need to repeat the C-x: Use +, =, -, 0, ESC for further adjustment. These keys call the function global-text-scale-adjust.

Thanks to this reddit thread for reminding me of these keys.