Can you attach a screenshot? *http://en.wikipedia.org/wiki/Screenshot *https://support.mozilla.org/kb/how-do-i-create-screenshot-my-problem Use a compressed image type like PNG or JPG to save the screenshot. ---- You can set the layout.css.devPixelsPerPx pref on the <b>about:config</b> page to 1.0 or on Windows 8 to 1.25 and if necessary adjust layout.css.devPixelsPerPx starting from 1.0 in 0.1 or 0.05 steps (1.1 or 0.9) to make toolbar icons show correctly. *http://kb.mozillazine.org/about:config See also: *https://support.mozilla.org/kb/forum-response-Zoom-feature-on-Firefox-22 Use an extension to adjust the text size in the user interface and the page zoom in the browser window. You can look at this extension to adjust the font size for the user interface. *Theme Font & Size Changer https://addons.mozilla.org/firefox/addon/theme-font-size-changer/ You can look at the Default FullZoom Level or NoScript extension if web pages need to be adjusted after changing layout.css.devPixelsPerPx. *Default FullZoom Level https://addons.mozilla.org/firefox/addon/default-fullzoom-level/ *NoSquint https://addons.mozilla.org/firefox/addon/nosquint/