Free Developer Tools

Find the provider behind any IPv4 or IPv6 address — an ISP for a home connection, a hosting provider or network operator otherwise — with the ASN, route and connection type.

Test if a website supports IPv6. One live DNS lookup checks a domain's AAAA records, name servers, and mail servers, and scores each layer so you can see where IPv6 coverage stops.

Analyze email headers to trace origin, verify SPF/DKIM/DMARC, and detect spam or spoofing.

Convert IPv6 to IPv4 instantly. Reads IPv4-mapped, 6to4, NAT64, IPv4-compatible, and Teredo addresses right in your browser.

Look up any AS number for the organization behind it, every IPv4 and IPv6 prefix it announces, its BGP upstreams, downstreams and peers, and the registry WHOIS record.

Check whether any IP address is a VPN, proxy, residential proxy, Tor exit node, or datacenter — or check your own connection in one click. Names the provider or hosting company where known.

Find the AS number announcing any IPv4 or IPv6 address, the organization operating that network, the registry that allocated it, and the route the address sits in.

This IPv4 to IPv6 converter tool instantly converts an IPv4 address into commonly used IPv6 address representations, so you can quickly use them for modern networks and testing.

Find IPv4 & IPv6 addresses up to 100 domain names at once with our free bulk domain to IP lookup tool.

Find every domain hosted on an IP address with a reverse IP lookup tool that discovers domains pointing to any IPv4 or IPv6 via DNS A records, complete with an exact domain count for security research, server audits, and infrastructure investigations.

Convert a decimal integer back into a readable IPv4 or IPv6 address instantly. Free decimal to IP converter, no sign-up, full range support.

Calculate IPv4 and IPv6 subnet details instantly, including network address, broadcast address, usable host range, subnet mask, and more.

Instantly convert any IPv4 or IPv6 address into its decimal integer representation with our free IP to decimal converter.

Resolve any IP address to its hostname with a free reverse DNS (PTR) lookup. Enter an IPv4 or IPv6 address and get the canonical hostname in seconds.

Shorten an IPv6 address by applying IPv6 compression rules to produce a clean IPv6 short form, also called IPv6 short notation.

An IPv6 Expander tool converts a compressed IPv6 address into its full, expanded form by restoring omitted zeros and groups so the address is displayed in a consistent 8-block format.