I use https://www.goatcounter.com/ and I'm very happy with it. It's open source and can be self hosted. Since there's no user tracking, it's GDPR compliant out of the box.
URL of the visited page. Referer header. User-Agent header. Screen size. Country name based on IP address. A hash of the IP address, User-Agent, and random number
As such, it seems to be processing user data that could be linked to an individual person.
I'd be cautious about the claim that GoatCounter is totally GDPR compliant (without a consent notice). You're safe, for now, on the basis that this doesn't seem likely to be tested in law.
It claims it's probably GDPR compliant, but it's pretty transparent about various possible caveats and such on the GDPR page[1].
"There should always be an option to add GoatCounter to your site without requiring a GDPR consent notice."