Privacy
SubnetLens is a calculator, not a service. Everything it does happens inside this browser tab.
What happens to the address you type
Nothing. Parsing an address, masking it to its prefix and working out the range are pure arithmetic, and all of it runs in JavaScript on your device. The address is never put in a URL, never sent to a server, and never written to storage. Close the tab and it is gone.
No account, no database, no lookups
There is nothing to sign in to, so there is no profile to hold. There is no database behind the tool, so there is nowhere for a subnet history to accumulate. SubnetLens also does no lookups of any kind: no WHOIS, no ASN, no reputation, no geolocation, no public-IP detection. It cannot tell you who owns an address, and it never asks.
What is stored locally
Two preferences, in this browser only: whether you last had Simple or Details open, and your light/dark choice. Both live in localStorage on your own device. No address, prefix or subnet is ever stored — not locally, and not anywhere else.
Analytics
SubnetLens ships without analytics, so nothing about your use of it is measured or sent on. If that ever changes, it would be limited to counts of anonymous events — the calculator opened, IPv6 mode used — and would never include an address, a prefix or a subnet. That rule is not negotiable.
Works offline
Because no calculation needs the network, the tool keeps working once the page has loaded, even with the connection dropped. That is a deliberate consequence of the design rather than a feature bolted on.
Who makes it
SubnetLens is a techvora tool. Questions about this page can go to Techvora.