Maybe I'm getting old, but the text in Matlab's built-in help browser is too small for me to read comfortably. It is possible to increase the font size using Ctrl-+, but every time a new help page is loaded, this change is lost

How can I permanently increase the font size?


This has been tested with Matlab R2015a on Linux, but I'd expect it to work on other platforms and maybe earlier versions, too.

Matlab's documentation is in the form of HTML, and the help browser is basically a web browser displaying locally stored files. There are several central style files, but the most important one appears to be


Open this file (as root / administrator) in a text editor, and append the line

html { zoom: 1.5; }

Adjust the number to your liking.

  • I have R2018a, and that file is not present in that folder. Ideas? – Travis Bemrose Sep 13 '18 at 17:42
  • I found the file ice_reset.css in that location. It already had the html tag so I made the changes. It was a BEAR trying to test out different values though. They sometimes seemed to take, but other times not. In the end, I realized that as long as I had any zoom specified, MATLAB help would ignore the value specified, but would preserve the last zoom level I'd switched to using the keyboard/mouse while viewing the help center. – Travis Bemrose Sep 13 '18 at 18:12

for R2014a, in /opt/MATLAB/R2015a/help/includes/product/css/reset.css, alter the value in the field


to your liking. start with 105% - it's sensitive.

Note that you don't have to restart Matlab, just close the help window and re-open after you save the file. You can iterate quickly to find your desired zoom.

  • 1
    Hi wis, and welcome to Super User. First, thanks for your contribution. You should be aware that we like answers to stand on their own, and not rely on any other answers already given to the question or rely overly on off-site resources. For that reason, I edited the file name directly into the question, and also removed the largely unrelated commentary at the end. Since you are new here, you may want to take the quick site tour to learn how we do things; we are different from forums that you may be used to. For more in-depth information, visit the help center or ask on Meta Super User. – user Apr 1 '16 at 18:50

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