This is due to the different settings of web pages. It is not the fault of the browser but the creator of that website. In many other cases, however, the fault of the operating system that determines the font of each character.

Hello Fire66, Try disabling graphics hardware acceleration.

You might need to restart Firefox in order for this to take effect, so save all work first (e.g., mail you are composing, online documents you're editing, etc.).

Then perform these steps:

• Click the orange Firefox button at the top left, then select the "Options" button, or, if there is no Firefox button at the top, go to Tools > Options.
• In the Firefox options window click the Advanced tab, then select "General".
• In the settings list, you should find the Use hardware acceleration when available checkbox. Uncheck this checkbox.
• Now, restart Firefox and see if the problems persist.

Additionally, please check for updates for your graphics driver by following the steps mentioned in the following Knowledge base articles:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

• Upgrade your graphics drivers to use hardware acceleration and WebGL

Did this fix your problems? Please report back to us!

Thank you.

Actually, it appears from the "More System Details" with your post that you already disabled hardware acceleration of graphics. This can reduce the smoothness of fonts (Firefox might not do the same anti-aliasing). If you are able to find an updated version of the Nvidia driver that is stable in Firefox -- assuming that is why the feature was disabled -- you'll be able to turn hardware acceleration back on and hopefully have a better experience.

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.

Note that zooming a web also can cause blurriness. I see that you have disabled full page zoom (View > Zoom > Zoom Text Only; browser.zoom.full = false)

• http://kb.mozillazine.org/browser.zoom.full

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

You can use an extension to set a default font size and page zoom on web pages.

• Default FullZoom Level: https://addons.mozilla.org/firefox/addon/default-fullzoom-level/
• NoSquint: https://addons.mozilla.org/firefox/addon/nosquint/

This could also be caused by HiDPI support in Firefox (try layout.css.devPixelsPerPx = 1)

See:

• 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.

Disabling hardware acceleration is not an option for me and is almost on par with "don't use firefox". To continue using hardware mode without the blur problem: I created a boolean value for layout.paint_rects_separately and setting it to true fixed this for me.

The article below may help to explain this: https://bugzilla.mozilla.org/show_bug.cgi?id=812695