IPv6 address inspector

Expand ::-compressed addresses to the full 8-hextet form, get the RFC 5952 canonical form, classify the scope (loopback / link-local / multicast / etc.), and derive the reverse-DNS PTR name. All client-side.

IPv6 address

Accepts bracketed URL form [::1], zone identifiers %eth0, and embedded IPv4 like ::ffff:192.0.2.1.

Why canonicalize? IPv6 addresses are ambiguous: 2001:DB8:0:0:0:0:0:1, 2001:db8::1, and 2001:0db8:0000:0000:0000:0000:0000:0001 are the same address. Allowlists, firewall rules, and log greps depend on a single form. RFC 5952 specifies it: lowercase, longest run of zeros compressed, no leading zeros in any hextet.

Keep hardening your site

This is one check of many. Run the rest — every tool is free, no account.

Scan your site's security headers →See the full platform →

Security headers scan

Grade your live response headers

TLS certificate scan

Grade chain, expiry, and key strength

Security headers builder

Emit a ready-to-paste header block

CSP analyzer

Grade your Content-Security-Policy

Cookie security audit

Check Secure, HttpOnly, SameSite

Mixed-content scanner

Find http:// assets on https pages

Open-redirect detector

Probe redirect params for abuse

HSTS preload checker

Grade against Chrome's preload list