This just happened. I was happily browsing away. Then I could not log in to my email, or any other site. Restarted laptop. Problem persists.

I had activated a Malwarebytes VPN earlier today. Thought it might be that but disabling it didn't help.

Problem persists on every browser I have.

Any ideas?

So, what does it say when you click on the WiFi icon on the lower right? You have to click on the "right" arrow to open it up. It should say Connected and Secured. When my WiFi is down, it says Not Connected and Secured. That means my computer is connected to the router, but there is no WiFi.

Have you tried rebooting your router?

Yes, restarting the router reconnected me. I should have thought of that first.