Knowledge base

Guides & knowledge base

Short, honest guides next to each tool — what it is, why it matters, how to check and how to fix.

Privacy & Connection

What is an IP address (and how to find yours)A plain-English guide to IP addresses: what they are, what sites can see, and how to check your…What is a DNS leak?What a DNS leak is, why it matters even with a VPN, and how to test which resolver actually han…How to check for a WebRTC leakWebRTC can reveal your real IP even behind a VPN. Learn what it is, how to test for a leak, and…What is IPv6 (and does it affect your privacy)?IPv6 explained in plain terms: what it is, why it exists, how it can bypass a VPN, and how to c…What is a browser fingerprint?How sites recognise you without cookies: what a browser fingerprint is, what goes into it, and …

Website & Domain

How to check a website's SSL certificateCheck an SSL/TLS certificate's expiry, issuer, chain and hostname match — and learn how to fix …What is SPF and how to check itSPF in plain terms: how it stops email spoofing, why it affects deliverability, and how to chec…What is DKIM and how to check itDKIM explained: how a cryptographic signature proves your email is genuine, and how to check yo…What is DMARC and how to check itDMARC ties SPF and DKIM together and tells receivers what to do with fakes. Learn how to check …How to check website redirects (301 vs 302)Trace a URL's full redirect chain, spot loops and HTTP→HTTPS gaps, and learn why 301 vs 302 mat…What are security headers (and which you need)?The HTTP headers that harden your site against XSS, clickjacking and downgrade attacks — what e…How to check if a website is down (for everyone or just you)Tell apart a real outage from a local problem, read the status codes, and set up monitoring so …