How nullcipher recognises it
Four dot-separated numbers each 0–255 with no leading zeros, not part of a longer dotted run (so 999.1.1.1 and 10.0.19045.2965 are not addresses). 0.0.0.0, 127.x.x.x and 255.255.255.255 identify nothing and are skipped.
This is the rule text of the “IPv4 address” detector in the masking engine, copied from the engine when this page was built. Detectors run in a fixed order and, where two overlap, the earlier one wins.
Example (fake)
192.0.2.44nullcipher replaces it with [IPV4_1]. 192.0.2.0/24 (TEST-NET-1) is one of the three blocks RFC 5737 reserves for documentation, so this address is never routed on the internet.
Why it matters in an AI chat
An IP address is not a credential, but it points at a specific connection. A public server address tells a reader which machine to probe; a home or office address is tied to one subscriber and often a rough location.
Private addresses such as 10.x.x.x or 192.168.x.x do not reach you from the internet, but a log full of them maps out how a network is laid out. nullcipher masks those too.
When you ask an AI about an error, the address itself rarely matters to the answer. A placeholder keeps the structure (same address, same placeholder) without the value.
If it already leaked
- There is nothing to revoke.
- For a server: make sure only the services you mean to expose are reachable on that address, and that anything private sits behind a firewall, because the address is now known.
- For a home or office connection there is usually nothing further to do; the address identifies the connection, not an account.
Sources
- RFC 5737: IPv4 Address Blocks Reserved for Documentation — checked 2026-09-23.
Open the full masking tool to mask a whole log, .env file or e-mail — every type at once — and restore the values in the AI's answer. Or see all 16 secret types and how to delete a chat you already sent.