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Why does Firefox scan my fonts directory?

  • 2 பதிலளிப்புகள்
  • 1 இந்த பிரச்சனை உள்ளது
  • 4 views
  • Last reply by jeffinputnam

Before FF starts it hangs and scans my font folder (all 600meg!) before it will do anything else, like connect to a website. This happens even if I simply restart the application after it's been running. And, its particularly worse after an update. Why can't it keep a list of available fonts that it can refer to rather than scan all over again? This can cause delays that run up to a minute and a half, as long as three and a little more.

I was going to rename the windows/Fonts folder to see what happens but being a system folder I can't.

Windows 10.

Before FF starts it hangs and scans my font folder (all 600meg!) before it will do anything else, like connect to a website. This happens even if I simply restart the application after it's been running. And, its particularly worse after an update. Why can't it keep a list of available fonts that it can refer to rather than scan all over again? This can cause delays that run up to a minute and a half, as long as three and a little more. I was going to rename the windows/Fonts folder to see what happens but being a system folder I can't. Windows 10.

All Replies (2)

I don't know what is happening there.

Could you test whether it makes any difference to hide user-installed fonts from web content? Here's the preference for that:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

(2) In the search box in the page, type or paste layout.css.font-visibility and pause while the list is filtered

Note: before Firefox 94

(3) Double-click the layout.css.font-visibility.level preference (or click the pencil button) to display an editing field, and choose a lower value, then press Enter or click the blue check mark button to save the change.

Note: starting in Firefox 94

(3) Double-click the layout.css.font-visibility.standard preference (or click the pencil button) to display an editing field, and choose a lower value, then press Enter or click the blue check mark button to save the change.

These are the recognized values:

  • 1 = only expose base system fonts
  • 2 = also expose fonts from optional language packs
  • 3 = also expose user-installed fonts (default)

More info on about:config: Configuration Editor for Firefox.


In case there is a problem with the startup cache, you can restart while clearing it using a button on the Troubleshooting Information page. Either:

  • "3-bar" menu button > Help > More Troubleshooting Information
  • (menu bar) Help > More Troubleshooting Information
  • type or paste about:support in the address bar and press Enter

In the upper right corner, look for the third button:

jscher2000 - Support Volunteer மூலமாக திருத்தப்பட்டது

Thanks for the quick response.

I've made the change in about:config from 3 (default) to 1 and it made a bit of a difference this morning when I had a clean boot to test on. If I look at the task manager I can still see FF scanning every font at boot-up and I just don't get it. You would think there would be an internal database of checksums that FF could scan at its leisure to see if anything had changed, and not at startup.

I was using "clear startup cache" to see if that helped and it didn't though, when FF gets bogged down and refuses to operate properly, I'll always restart that way and it seems to help.

Part of the problem might be that I'm on a 10 year old computer and the world has gone to color tv and portable phones since it was built.