There’s a lot to be said for the “slim, fast-loading” bit! HN is my go-to “is my internet connection at all functional?” web page. And when T-Mobile cuts me off when I run over my data allotment each month, at least I can read the comments.
Even better for that purpose is neverssl.com. As the name implies, it’s http-only, so misconfigured WiFi portals will still intercept and load their captive login page.
I use example.com which is also guaranteed to not be https. If I'm asking someone else to type the URL in, it is easy to say "example.com" and know they can spell it correctly. It's also very light weight.
I believe you also get a Netflix subscription included, which saves you an additional $10/month if you're already out of pocket for said subscription. Check it out! Happy T-mobile customer for 18 years.
asdlkfjhsdklfh, for example. I assume you are joking, the point is to enter a random string to see if google searches for it; as entering a fixed string takes longer.