The most surefire way to know if a site is behind Cloudflare (orange cloud is on) is by hitting /cdn-cgi/trace (e.g. https://news.ycombinator.com/cdn-cgi/trace) which is the debug output from Cloudflare’s HTTP server. There’s no way to my knowledge that route can be disabled or overriden.

Anyway, no, HN is not on Cloudflare, at least at the moment.

https://www.cloudflare.com/cgi-bin/trace/ is a 404

That's because it's cdn-cgi and not cgi-bin.

HN hasn't been on Cloudflare for almost a year now. Straight to their origin server it seems.

Doesn't seem so http://www.doesitusecloudflare.com/?url=https%3A%2F%2Fnews.y...

I've seen the "checking your browser" on HN message quite a few times, especially when I use a VPN, and I'm pretty certain it's the CF one.

Maybe it's turned on selectively for high traffic / bot situations?

I just put in my own Cloudflare-enabled website and it came back negative as well.

FWIW, this site doesn't seem accurate. I used it against my site that is definitely using cloudflare and it incorrectly reported it as not :p

for our sites behind cloudflare, it seems to be a routing issue (among possible other things) - some visitors can still access the sites, others can't. traffic went down roughly 60%.

Seems to be intermittent, and perhaps dependent on which POP you are hitting. I have been getting PagerDuty alerts that are flapping between triggered and resolved.

We have several websites running behind Cloudflare. Only one out of our 8 or so seem affected