Ask HN: What do you use to test website performance?

I've used webpagetest.org and gtmetrix.com in the past. It's been a while so I thought I'd ask HN in case there are more modern ways of checking for opportunities for performance improvement/adherence to "best practices".

I know they're imperfect but I also use these tools for getting a feel for the care that has gone into crafting a site.

Anyone have any resources for doing a quick "yep it looks OK" website checks?