Is cdn.optimizely.com Safe?

Optimizely is an A/B testing platform for website owners to test out multiple versions of a page at the same time. When visiting the same page on a website, one person might get version "A" whilst another might get version "B". This is a legitimate business usage case, and shouldn't be ranked poorly for "tracking" users. That's exactly how it works, on purpose, by using demographic details (such as location based upon IP address), to serve up different content. This is not malicious.

Doesn't seem to be a bad site from what I can see. Safe Browsing Diagnostic page for cdn.optimizely.com What is the crrent listing status for cdn.optimizely.com? This site is not currently listed as suspicious. What happened when Google visited this site? Of the 145 pages we tested on the site over the past 90 days, 0 page(s) resulted in malicious software being downloaded and installed without user consent. The last time Google visited this site was on 2014-08-10, and suspicious content was never found on this site within the past 90 days. This site was hosted on 24 network(s) including AS20940 (AKAMAI-ASN1), AS15133 (EDGECAST), AS701 (UUNET). Has this site acted as an intermediary resulting in further distribution of malware? Over the past 90 days, cdn.optimizely.com did not appear to function as an intermediary for the infection of any sites. Has this site hosted malware? No, this site has not hosted malicious software over the past 90 days.