Try Clear Recent History

Also:

Have you tried Firefox's zoom feature? This will help increase the size of web pages.

• To make things bigger, press Ctrl and &#43 at the same time.
• To make things smaller, press Ctrl and - at the same time.
• To reset the size back to normal, press Ctrl and 0 at the same time.

You can also use the NoSquint. add-on to change the default zoom level for all websites at once. After setting your global zoom level, you can still fine-tune the zoom on individual sites.

Using NoSquint:

1. After installing NoSquint, make sure you have the Add-on Bar displayed:
   • Right-click the new tab button ("+") or a blank area of the tab bar to the right of it and choose Add-on Bar from the shortcut menu.
2. Click the % on the Add-on Bar to call up site preferences, then click the Global Settings button, then the Zooming tab.
   • You can experiment with sizes larger than 125%, but it's not recommended that you go higher than 150% unless you have a large high-resolution monitor.

If there are particular sites that still present a problem, feel free to post their URLs.

Please let us know if this helped you!

Thank you.

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.

Reset the page zoom on pages that cause problems.

• View > Zoom > Reset (Ctrl+0 (zero); Command+0 on Mac)

• http://kb.mozillazine.org/Zoom_text_of_web_pages

If you have made changes to Advanced font settings like increasing the minimum/default font size then try the default minimum setting "none" and the default font size 16 in case the current setting is causing problems.

• Tools > Options > Content : Fonts & Colors > Advanced > Minimum Font Size (none)

Make sure that you allow pages to choose their own fonts.

• Tools > Options > Content : Fonts & Colors > Advanced: [X] "Allow pages to choose their own fonts, instead of my selections above"