For some reasons, I can’t install Railgun on my host server. Will it still have any benefits to activate Railgun on Cloudflare? Will it increase the speed of third-party scripts such as Adsense.
a) Yes, it will still increase the performance
b) Nope
c) It will affect your website / Adsense performance.
Nope. Railgun needs both endpoints functioning to make that speeded up connection. From the support document: "Unlike other Cloudflare features, it does require a program to be installed on or near the origin web server. "
I don’t believe you can even activate Railgun if a server hasn’t been set up.
Also, nothing can directly increase the speed of third-party scripts like adsense, as the browser itself makes a request to Google’s servers. Ad load times are entirely dependent on how fast Google can bid and serve an ad to the browser, and how fast the browser can render your webpage.
If you’re looking to make ads load faster on browsers, consider auditing how many scripts, trackers, “like buttons”, etc that you have on the page. The more javascript the browser has to load at once, the slower loading ads will take.