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:nationalfuelgas.com/documents/NFG_AR16_Web.pdf redirected to: nationalfuelgas.com/404.asp...
favicon.ico:
site title: Untitled Page
Url ContentHyperText Markup Language (HTML)
MIME Type / Internet Media Typetext/html
MIME Type text
File Extension.html
More Details (link to:)Wikipedia: HTML
Powered by: Very Tiny URL Shortener at https://vturl.net VeryTinyURL

Header

HTTP/1.1 301 Moved Permanently
Cache-Control No-Cache
Content-Type text/html; charset=UTF-8
Location htt????/nationalfuelgas.com/documents/NFG_AR16_Web.pdf
Server Microsoft-IIS/8.5
Strict-Transport-Security max-age=31536000; includeSubDomains
X-XSS-Protection 1
Date Fri, 19 Oct 2018 09:07:12 GMT
Content-Length 593
HTTP/1.1 302 Redirect
Cache-Control No-Cache
Content-Type text/html; charset=UTF-8
Location htt????/nationalfuelgas.com/404.aspx
Server Microsoft-IIS/8.5
Strict-Transport-Security max-age=31536000; includeSubDomains
X-XSS-Protection 1
Date Fri, 19 Oct 2018 09:07:12 GMT
Content-Length 159
HTTP/1.1 200 OK
Cache-Control private,No-Cache
Content-Type text/html; charset=utf-8
Server Microsoft-IIS/8.5
Set-Cookie ASP.NET_SessionId=o3w2gcywuhkavu55ra3kko45; path=/; HttpOnly
X-AspNet-Version 2.0.50727
Strict-Transport-Security max-age=31536000; includeSubDomains
X-XSS-Protection 1
Date Fri, 19 Oct 2018 09:07:12 GMT
Content-Length 5367

Load Info

page size5367
load time (s)5.18844
redirect count2
speed download1034
server IP205.235.175.200


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