How to Check HTTP Headers of Any Website
HTTP headers reveal how a server is configured — caching, security policies, server software, and more. Here is how to inspect headers and what to look for.
How-to guides
HTTP headers reveal how a server is configured — caching, security policies, server software, and more. Here is how to inspect headers and what to look for.
Checking password strength goes beyond length. Here is what a strength checker actually measures, what makes a password truly strong, and how to test yours.
Regular expressions are powerful but hard to remember. Here is the essential regex cheat sheet plus how to test and debug any regex pattern online.
Cloudflare hides a website's real server IP behind its proxy. Here is how Cloudflare IP resolution works and why the real IP sometimes leaks.
Open ports are potential entry points for attackers. Here is how to scan for open ports, what each common port does, and how to close the ones you do not need.
Fake and disposable email addresses inflate your list, trigger spam filters, and waste resources. Here is how to verify any email address before you send.
AI-generated text is everywhere. Here is how AI detectors work, which signals they check, and the best free tools to detect ChatGPT and other AI writing.
UTM parameters let you track exactly where your traffic comes from in Google Analytics. Here is what each parameter means and how to build UTM links correctly.
Minified JSON is unreadable. Invalid JSON breaks your API calls. Here is how to format, validate and fix JSON errors instantly — with examples.