SubnetBuddy

SubnetBuddy is the ultimate networking companion for IT professionals, students, and anyone working with IP addresses and subnets. Designed for speed and simplicity, it works completely offline — no internet connection required. KEY FEATURES: Subnet Calculator — Enter any IP address and CIDR notation to instantly calculate network address, broadcast address, usable host range, wildcard mask, and total hosts. VLSM Calculator — Efficiently divide a network into variable-length subnets based on your specific host requirements. Perfect for optimizing IP address allocation. Binary/Decimal Converter — Quickly convert between binary and decimal formats for IP addresses and subnet masks. CIDR Reference Table — A handy quick-reference chart for all CIDR notations from /1 to /32, showing subnet masks, wildcard masks, and available hosts at a glance. IPv4 Class Identifier — Instantly determine the class (A, B, C, D, E) of any IP address along with its default subnet mask and address range. 100% Offline — All calculations happen on-device. No data is sent anywhere, ever. Use it in the field, in the server room, or during an exam. Clean, Modern UI — A sleek dark interface designed for readability and fast navigation. Copy results to clipboard with a single tap. PERFECT FOR: Network engineers and administrators CCNA, CompTIA Network+, and IT certification students Help desk and support technicians Anyone learning about IP networking SubnetBuddy was built by a network professional who needed a fast, reliable, and ad-free subnet tool that just works. No sign-ups, no ads, no tracking — just pure networking utility in your pocket. Download SubnetBuddy today and never struggle with subnet math again.