Calculate subnet masks, network addresses, broadcast addresses, and usable host ranges. Everything runs locally in your browser — nothing is uploaded.
Calculate CIDR subnet ranges — network address, broadcast, first/last host, total hosts, and netmask.
Visualize IP subnet divisions with a hierarchical tree view for network planning. Everything runs locally in your browser — nothing is uploaded.
Generate random TCP/UDP port numbers from well-known, registered, or dynamic ranges. Useful for network testing, Docker port mapping, and firewall configuration.
Anonymize IP addresses in log files by masking octets while preserving network structure for analysis.
Calculate heart rate training zones by age. Find your target heart rate ranges for different exercise intensity levels. Everything runs locally in your browser — nothing is uploaded.
Subnet Calculator lets you calculate subnet masks, network addresses, broadcast addresses, and usable host ranges. Everything runs locally in your browser — nothing is uploaded.. It works on any device with a modern web browser.
Calculate subnet masks, network addresses, broadcast addresses, and usable host ranges. Everything runs locally in your browser — nothing is uploaded. It runs entirely in your browser — no software installation or data uploads required.
Paste or type your content directly into the provided text area.
Yes. After the initial page load, Subnet Calculator runs entirely on your device with no internet connection needed. All processing is done locally.
Calculate subnet masks, network addresses, broadcast addresses, and usable host ranges. Everything runs locally in your browser — nothing is uploaded. All processing runs locally — no code is sent to any server.
Tools cover JavaScript, CSS, HTML, SQL, Python, JSON, XML, CSV, and more. Check the tool description for specifics.
Yes. Since processing is local, performance depends on your device. Most operations handle large files without issue.
Yes. Formatters use well-known libraries (sql-formatter, Prettier-compatible patterns) and follow widely adopted rules.