Can you post a link to that web page? - Reset the page zoom on websites that look wrong: 'View Zoom Reset' (Ctrl + 0 (zero)) See If you increased the minimum font size then try the default setting 'none' as a high value can cause issues like you described. Firefox Preferences Content: Fonts & Colors Advanced Minimum Font Size (none). Fdf-converter 8.0.1 for mac. Firefox Preferences Content: Fonts & Colors Advanced X 'Allow pages to choose their own fonts, instead of my selections above' - See also Websites look wrong.