Always Online™ is a feature that caches a static version of your pages in case your server goes offline.
If your origin server is ever unavailable, Cloudflare will serve a limited copy of your cached website to keep it online for your visitors. Cloudflare builds the Always Online version of your website, so your most popular pages are represented. Cloudflare is caching pages when you see the crawler in your logs.
Mozilla/5.0 (compatible; CloudFlare-AlwaysOnline/1.0; +https://www.cloudflare.com/always-online) AppleWebKit/534.34
We crawl free customers once every 7 days, Pro customers once every 3 days, and Business and Enterprise customers daily. More details
If you’re a Cloudflare customer, you can turn this crawler off in the settings overview page of your Cloudflare settings.