Web Reconn Tools

1. Shodan

https://www.shodan.io/www.shodan.io

2. Censys

Censys SearchCensys

3. Netcraft

What's that site running?What's that site running? | Netcraft

4. Security Headers and Threat Intelligence

Analyse your HTTP response headerssecurityheaders

Threat Intelligence Platform (TIP) | Integrate #1 Cyber Threat Intel APIsthreatintelligenceplatform.com

5. View DNS

https://viewdns.info/viewdns.info