Good afternoon, all.

The past few days have brought an interesting problem: Firefox is ridiculously slow to launch, or hangs up for a good long time if the MacBook has been asleep. What gives?

Up until a week or so ago, I could close the lid and walk away, leaving Firefox active. When I'd come back and unlock the MacBook, I could dive right back into whatever I was surfing when I walked away. Not so, the past few days. I've been having to quit Firefox, then restart it, then still wait a minute or more before it would navigate to any site. (I've written this from Safari, while waiting for Firefox to churn up.)

If I launch Firefox in troubleshooting mode, then things go smoothly. I can understand that -- it launches without add-ins. I only have one add-in attached, so I turned it off, then quit and relaunched Firefox. Still wicked slow.

Last night I did the uninstall/reinstall thing on Firefox, without positive results.

I'm at a loss now. I didn't actively change any settings (might have done something accidentally, I suppose). I've run the usual virus scans, tossed out all the history, cleared caches, and all that other fun stuff.

System details, for what they're worth:
Firefox 137.0.2 (64-bit)
macOS Catalina, 10.15.7
Mid-2012 MacBook Pro 15"

Has Firefox had a software update recently? Could be a bug that affects Intel processors if they are moving to more M silicon native code.

Haven't seen any issues on my M3 iMac and M3 Macbook Air but I'll see if I can duplicate the issue. My old Macbook 12 is Intel so I'll give that a try too.

Who is your ISP? Are you running a VPN? What DNS server(s) do you have configured? I have seen ISP's DNS servers be slow to answer queries not made from within their netblock. A delay of some seconds before a transfer (e.g. populating a web page) is often indicative of a DNS fallback (no answer from first DNS server queried, falling back to a secondary server).

This can also happen if the ISP's premises router is configured as a caching DNS server and you get a cache miss on a query. This situation can often be diagnosed when the first query for an address is slow, then subsequent ones are fast.

ISP is Shentel. I'm not using VPN at the moment. I'm not sure (yet) how to answer the DNS server question. Would the DNS server work differently for Firefox vs Safari? Safari is still as quick as normal; it's just Firefox that's giving me trouble.

Your DNS are set in the network settings
https://support.apple.com/guid...s-on-mac-mh14127/mac

Google DNS is 8.8.8.8. There is a beneficial Quad 9 DNS provider but setting that up is now very obtuse.

Most ISP create default DNS that benefit the ISP, not you. These can be very slow.

Thank you for the link and guidance.

The DNS server listed is my own router. I'll look up the 8.8.8.8 thing in a moment. First, though, I'll go reset the router and the cable modem.

What's wrong with using the native browser Safari?

It's built to be a part of the OS and is always going to work best with it rather than a standalone browser.

I tried using Chrome on my iPhone and just found it far too clunky, Safari is good enough.

The DNS should be a commercial entity, not your router IP.

quote:

Originally posted by vthoky:

The DNS server listed is my own router. I'll look up the 8.8.8.8 thing in a moment. First, though, I'll go reset the router and the cable modem.

You computer is getting DNS information from your router, which is acting as a relay. You need to look at the DNS setting in your router.

CloudFlare is one option: 1.1.1.1

Google is another: 8.8.8.8 or 8.8.4.4

Quad9 is another: 9.9.9.9

Any of these should do the job for you. You can learn more if you google "DNS Server."