Free network and browser tools that run in your browser
Inspect your browser, calculate IPv4 subnets, parse user agents and URLs, and look up common ports — 100% in your browser with no uploads, no API calls and no signup.
Browser Info
See everything detectable about your browser, OS, device, screen and settings — locally, with no requests.
Subnet Calculator
Compute IPv4 network, broadcast, usable host range, host count, wildcard and mask conversions from an address and CIDR.
User Agent Parser
Paste any user agent string to parse the browser, engine, OS, device and CPU.
URL Parser
Break a URL into protocol, host, port, path, query parameters and hash — then edit and rebuild it.
Port Reference
Searchable table of common TCP/UDP ports, services and protocols.
Private network and browser tools, right in your browser
Every tool on Network Tools runs entirely on your device using JavaScript and built-in browser APIs. Nothing you type is ever uploaded to a server, and these tools make no external API calls — calculations and lookups happen instantly and completely privately. There's no signup and no tracking of your inputs.
Want to inspect your browser, calculate an IPv4 subnet, parse a user agent string, break down a URL or look up a common port? Pick a tool above — results appear locally on your device.