IP Range to CIDR Converter
Paste a CIDR block such as 192.168.0.0/20 to get its network address, usable host span, broadcast and mask, or paste two addresses such as 10.0.0.5-10.0.0.200 to get the minimum non-overlapping CIDR list that covers them. IPv4 and IPv6 are both supported, and the arithmetic uses big integers, so an IPv6 /64 does not overflow.
Your data is processed only inside this browser tab.
How to use
Turn an IP range into the smallest CIDR set, or a CIDR block back into its range. IPv4 and IPv6. Your data is processed only inside this browser tab.
FAQ
Can the returned blocks overlap?
No. The range mode returns the canonical prefix list, sorted from the start address, with no gaps and no overlaps inside it.
Is my address data sent anywhere?
No. Parsing and arithmetic happen inside this page and the tool makes no network request at all.
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