Hi, your browser identified itself as Microsoft Edge, so it's hard to tell what version of Firefox you are running. Which one is it?

Is the problem that Firefox only uses Arial and Times New Roman on every site, regardless of what fonts the site specifies?

Or that you have customized your fonts at the system level and Firefox ignores your font customization?

Or that sites can specify and Firefox will use different built-in fonts (like Comic Sans MS) but can't use web fonts (downloadable fonts)?

For some things to check, see this thread:

https://support.mozilla.org/questions/1397374

Thank you for your response. I didn't think it mattered what Firefox version I was using since I said this has been going on for months across all updates. Right now I'm using Firefox portable but the problem is also with the Firefox installed version which I sometimes use though recently have deleted it wondering if using both may be the problem but it's not. I've tried Waterfox and the fonts all display in that fork. i haven't uninstalled Waterfox to see if it's having some effect because this was going on before its installation. I've always allowed pages to choose their own fonts and so that's never been part of the equation. But, yes, the issue is that Arial and Times New Roman are substituted for all the custom fonts I'm aware of. I haven't checked every system font to see if some of those might be displayed because most of the time I don't know what font a webpage is using but I can see in a Chrome-based browser that a different font is being displayed. Since I've clean installed there can't be any extensions interfering with the display of fonts. I thought there may be some about:config setting that's been altered because I do change settings there but again a clean installation should I think solve that but correct me there if I'm wrong.

Note that current releases have a fix for Google Material fonts, so at least those should work even if you do not allow pages to their own fonts.

• browser.display.use_document_fonts.icon_font_allowlist

You can check the Web Console (Tools -> Web Developer) for messages about blocked content and about the presence of mixed or unsafe content.

• https://firefox-source-docs.mozilla.org/devtools-user/web_console/

You can check the Network Monitor to see if content is blocked or otherwise fails to load.

• https://firefox-source-docs.mozilla.org/devtools-user/network_monitor/

If necessary use "Ctrl+F5" or "Ctrl+Shift+R" (Mac: Command+Shift+R) to reload the page and bypass the cache to generate a fresh log.

You can right-click and select "Inspect" to open the built-in Inspector with this element selected.

• https://firefox-source-docs.mozilla.org/devtools-user/page_inspector/how_to/open_the_inspector/
• https://firefox-source-docs.mozilla.org/devtools-user/page_inspector/how_to/examine_and_edit_html/

You can check in the Rules tab in the right panel in the Inspector what font-family is used for selected text. You can check in the Fonts tab in the right panel in the Inspector what font is actually used because Firefox might be using a different font than specified by the website.

• https://firefox-source-docs.mozilla.org/devtools-user/page_inspector/how_to/edit_fonts/

That Google's fonts may be an exception isn't a solution. I can't say if they exclusively display or not or why that would lead to a solution. I can say that all fonts display at font download sites so what they're doing differently in their code is unclear. You say to check for "messages about blocked content and about the presence of mixed or unsafe content" but I fail to see what that has to do with fonts not being displayed, much less not displayed offline as well, and if you think average users can navigate a console, a network monitor, and inspector is presumptuous. If it's an OS problem why would it just affect Firefox.

A better solution would be to just switch over to a chromium browser. I supported Firefox and gecko initially because it was open source but so is chromium. I also didn't want to support big for-profit corporations but there are forks of chromium that aren't developed by such entities. I'm not sure why I'm hanging on to Firefox except I guess sentiment, I hate to let a browser I've used and supported for so long go under but I just don't see it competing with chromium browsers, certainly not with chromium's implementation of CSS which is leaving Firefox in the dust.

If a complete uninstallment of every Mozilla file on my computer, and the re-installation of Firefox didn't solve the problem, the problem I have to assume isn't solvable tho I had hoped someone here might have a last ditch solution before I delete Firefox entirely from my drive and move on. Thank you, Firefox, for providing years of service, but some home repair problems can only be solved by moving to a new house. So be it.

I am going to guess that in Tools -> Settings on the General Tab, you've clicked the Advanced button next to Fonts and that you've checked Allow pages to choose their own fonts, instead of your selections above. Screenshot: https://i.imgur.com/qFrgwBb.png

Just something to verify.