Subnet calculator and CIDR converter
Calculate a network, convert an IP range, combine or split subnets.
Open toolPassive DNS, email and registry diagnostics plus instant IP calculations. NekoIP never connects to the website, mail server or TLS endpoint you enter.
Enter one value and NekoIP will choose the appropriate passive tool.
Start with a common task. You only need one value in most cases.
Calculate a network, convert an IP range, combine or split subnets.
Open toolFind a website address, mail server, TXT verification or another DNS record.
Open toolCheck whether a domain's email protection records are configured correctly.
Open toolGet the main DNS, email and registration facts in one check.
Open toolConverters and registry tools for more specific questions.
Convert an IP address to expanded, numeric, hexadecimal or binary form.
Open toolFind the domain name associated with an IP address.
Open toolFind public registration data for a domain, IP address or ASN.
Open toolSee which DNS service your device is actually using.
Open toolPassive DNS, email and registry diagnostics plus instant IP calculations. NekoIP never connects to the website, mail server or TLS endpoint you enter.