IP & Network Tools
Find out what your connection looks like from the outside, and do the subnet maths.
- DNS Leak TestCheck whether your DNS requests are leaking outside your VPN.Partly server-side
- DNS LookupEvery record a domain publishes, with what they imply about its mail and certificates.Secure lookup
- IP Address LookupLook up the location, ISP and network of any IP address.Secure lookup
- Subnet CalculatorNetwork, broadcast, host range and mask for any IPv4 address and prefix.Runs in your browser
- VPN Protocol RecommenderFive questions, then a straight answer — including “you do not need the stealthy one”.Runs in your browser
- WebRTC Leak TestCheck whether WebRTC is exposing your real IP behind a VPN.Runs in your browser
- What Is My IPSee your public IP, location, ISP and network — instantly.Secure lookup
- ASN LookupWhich network announces an address, and which prefix it sits in.Third-party data
- CIDR CalculatorTurn a CIDR block into its address range — or a range into the smallest blocks that cover it exactly.Runs in your browser
- Internet Speed TestMeasure your real download and upload speed, ping and jitter.Partly server-side
- IPv4 to IPv6 ConverterThe four ways an IPv4 address appears inside IPv6 — and why none of them is “your IPv6 address”.Runs in your browser
- Subnet Mask ConverterConvert between /24 and 255.255.255.0, in either direction, with the whole table.Runs in your browser
What these tools have in common
Two different jobs live in this section. One is finding out what your own connection exposes — the address websites see, the ISP behind it, whether you have working IPv6, which resolver answers your DNS queries. The other is the arithmetic: subnets, CIDR blocks, address ranges, masks.
They sit together because they answer the same underlying question from opposite ends. "What is my IP" is asking what a network looks like from outside; a subnet calculator is asking what it looks like from inside. Network engineers move between the two constantly.
Everything here that can run in your browser does. The lookups that genuinely need a server — geolocation of an arbitrary address, for instance, which requires a database no browser ships — say so on the page.