Today I learned… that you can change the font size in IntelliJ IDEA across all editor tabs and consistently! It’s not a missing feature and you don’t have to rely on the awkward trackpad zoom feature.
Here’s how you do it (on a Mac, anyway).
Go to IntelliJ IDEA —> Preferences —> Editor —> Colors & Fonts —> Font
On the right, look for Scheme name.
Click the Save As… button and give it a unique name.
This step is essential! If you don’t do this step, changes you make to Size further down won’t stick, and IntelliJ won’t tell you why. (The popup is titled “Save Color Scheme” so it’s easy to see why users might overlook its effect on the ability to save font size.)
Now alter the Size setting and you should see the typeface preview change to reflect your input. Press OK and you’re done!
Googling this problem, I found some conflicting answers about how to increase IntelliJ’s font size.
Many IntelliJ users recommend the “trackpad zoom” solution (which you have to enable in Preferences —> General —> Change font size (Zoom) with Command+ Mouse Wheel), but relying on zooming in results in a patchwork of mismatched zoom levels across all your tabs, and you have to manually re-zoom each tab. I wanted a consistently larger font-size across all tabs, with no manual zoom step, and this did the trick!