If you are not sure if the website you want to visit is safe, you can check it out here. Enter the address (url) of the website and see the invisible elements, such as a header or meta data.
site address:pagead2.googlesyndication.com/pagead/js/r20171129/r20170110/osd.j...

Header

HTTP/1.1 200 OK
P3P policyref= htt???/www.googleadservices.com/pagead/p3p.xml , CP= NOI DEV PSA PSD IVA IVD OTP OUR OTR IND OTC
Timing-Allow-Origin *
Date Sat, 16 Dec 2017 06:59:12 GMT
Expires Sat, 30 Dec 2017 06:59:12 GMT
Cache-Control public, max-age=1209600
Content-Type text/javascript; charset=ISO-8859-1
ETag 16709551129238551184
X-Content-Type-Options nosniff
Content-Disposition attachment; filename= f.txt
Content-Encoding gzip
Server cafe
Content-Length 29530
X-XSS-Protection 1; mode=block

Load Info

page size29530
load time (s)0.01315
redirect count0
speed download0
server IP216.58.204.226


* all occurrences of the string "http://" have been changed to "htt???/"