TalkingQuickly's Today I Learned

Cloudflare Free SSL on Heroku

It's been bugging me for ages that I could only access this TIL instance via the Heroku URL, not the til.talkingquickly.co.uk subdomain. Turns out that for SSL to be terminated by Cloudflare, rather than using the custom subdomain CNAME from Heroku, e.g. yourdomain.herokudns.com, as a CNAME entry in Cloudflare, instead you should use the Heroku provided URL, e.g. YOURAPP.herokuapp.com.

From: https://thoughtbot.com/blog/set-up-cloudflare-free-ssl-on-heroku