Tools

DNS Checker

• https://www.whatsmydns.net/ – web site propogration
• How to find all subdomains of a domain
• Search for hosts/SSL

SSL Checker

• https://www.ssllabs.com/ssltest/
• https://www.sslshopper.com/ssl-checker.html

Online Malware Scanner

• https://sitecheck.sucuri.net

Site Checker

• https://geopeeker.com
• https://shotsherpa.com
• https://www.browserling.com
• https://search.google.com/test/rich-results

Google Search Console

• https://search.google.com/test/mobile-friendly

Web site Tools

• https://www.uptrends.com/tools/traceroute

Site Speed

• https://gtmetrix.com
• https://developers.google.com/speed/pagespeed/insights/
• https://tools.pingdom.com/fpt/
• https://developers.facebook.com/tools/debug/og/object/
• https://www.uptrends.com/tools/uptime

Email Checker

• mail-tester.com – Test the Spammyness of your Emails.
• https://dkimvalidator.com/ – Test SPF/DKIM/DMAC.
• MXtoolbox.com – Text your DNS MX records.
• SenderScore.org – Know your sender reputation
• https://www.checktls.com/TestReceiver

IP

• https://ip.serverok.in
• https://search.censys.io/ – Find website IP address history.

WHOIS

• Domain Dossier
• https://internic.net/whois.html – check IP of name server

Security

• https://www.shodan.io/ – Shodan is the world’s first search engine for Internet-connected devices. Discover how Internet intelligence can help you make better decisions.

CIDR

* https://www.ultratools.com/tools/netMask CIDR to Netmask (for hosts.allow)
* https://ip2cidr.com
* https://cidrcalculator.com/ipv4/ip-range-to-cidr/?cy=USD
* [http://www.subnet-calculator.com/cidr.php IP CIDR Calculator]

DNS Checking

* http://www.dnsinspect.com
* http://www.dnsstuff.com/tools
* http://www.intodns.com
* http://dnscheck.pingdom.com
* http://ViewDNS.info

Ping

* https://www.dnsstuff.com/tools
* https://host-tracker.com/ (check your site availability in different country)

TraceRoute

* https://www.traceroute.org (traceroute from various locations)
* https://tools.pingdom.com/ping/

File System

* https://www.clonespy.com (Remove Duplicate files)

Malware

* https://sitecheck.sucuri.net/scanner/ (scan site for malware)
* https://www.unmaskparasites.com
* https://www.stopbadware.org/clearinghouse/search

Domain

* https://www.domainsbot.com
* https://www.whois.sc