Hello,

Firefox on Windows is now following display scaling options which may render text larger on high resolution displays. You can adjust your screen resolution. To modify it do the following:

• Type about:config into the Firefox address bar and tap on the Enter key.
• If the warning This might void your warranty appears, click I'll be careful, I promise.
• Search for layout.css.devPixelsPerPx

• Double-click on layout.css.devPixelsPerPx to modify its value. The default is -1.0 in Firefox 22 and above. Change it to 1.0 to make it work like in previous Firefox versions.

If necessary, further adjust the value in 0.1 or 0.05 steps. Use values between 1.0 and about 0.5 to reduce elements in size. Use values greater than 1.0 to increase size. For example, a value of 1.25 will increase font size to 125% to accommodate the default DPI setting in Windows 8. Double check the value that you enter. Setting a too small value will make everything disappear and a too large value will blow things up.

If web pages still need to be adjusted then you can look at the Default FullZoom Level or NoSquint extension.

To adjust the font size for the user interface, you can use the Theme Font & Size Changer extension.

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

Thank you.

Hi Waka Flocka Flame.

I’ve been testing your suggestion now for a little while ...

The "about config" suggestion did not work so I installed the Default Fullzoom Level addon.

For the most part this work 4 out of 5 days.

The days it doesn’t work ... Firefox opens and all regular web sites I visit have been reset back to 100%.

I have noted that there was nothing unusual in the previous day/night shut down of Firefox and my PC.

Oh the other weird thing I've noticed which may or may not be related .... the day when Firefox zoom resets ... I noticed Firefox loses other functions of "recently closed windows and recently closes tabs" under history .

I’ve have noticed this the last 3 times ... when I’ve encounter the reoccurrence of the lost zoom problem.

On the problem days, do you notice any other settings / customizations missing?

Is the Default FullZoom extension still installed, or do you need to reinstall it?

Some external software may "clean" your Firefox settings, such as CCleaner. In that case, you can make an exception for your Firefox settings folder.

Hi Jscher ...

Thank you ... I should have added.

The default FulZoom addon is still installed and appears fully functional in that ... when the lost zoom problem occurs ... I open all the usual websites I go to ... and using Default Zoom I reset which it the level I require.

I then close all tabs (thats when I notice the "recently closed tabs" functions isnt working) and firefox .... and then restart.

I don't to my knowledge have anything like CCleaner installed

Make sure that you do not run Firefox in (permanent) Private Browsing mode (Never Remember History).

• https://support.mozilla.org/kb/Private+Browsing

• Tools > Options > Privacy > Firefox will: "Use custom settings for history"
• Deselect: [ ] "Always use private browsing mode"

In case you are using "Clear history when Firefox closes":

• do not clear the Site Preferences

• Tools > Options > Privacy > Firefox will: "Use custom settings for history": [X] "Clear history when Firefox closes" > Settings
• https://support.mozilla.org/kb/Clear+Recent+History

Note that clearing "Site Preferences" clears all exceptions for cookies, images, pop-up windows, software installation, and passwords.

Thank you for your reply.

My firefox does not use default private browsing.

Nor do I have "Clear site preferences" sellected.

refer to

• Webpages are large and blurry after updating Firefox - how to fix
• How to fix preferences that won't save