Eight free browser-based tools for network engineers and students — subnetting, VLAN planning, bandwidth sizing, binary conversion, router lookups and exam practice. Nothing to install, no account needed, and every calculation runs in your browser.
Subnetting & Addressing
Subnet Calculator
Enter any IPv4 address and CIDR prefix to get the network address, subnet mask, broadcast address, usable host range, wildcard mask and binary mask. Handles /31 and /32 correctly.
VLAN Calculator
Plan a multi-VLAN network. Add departments, pick a subnet size, and get an aligned IP plan with gateways and a ready-to-paste Cisco IOS configuration.
IP to Binary Converter
Convert any IPv4 address to binary, hexadecimal and its 32-bit decimal value, with a per-octet breakdown. Includes the manual conversion method for exams.
Speed & Capacity
Bandwidth Calculator
Work out how much bandwidth an office or home actually needs, based on user count, concurrency and the applications in use — with headroom built in.
WiFi Speed Test & Analyser
Run a speed test, then find out what your Mbps figure means for streaming, gaming, calls and how many people your connection can support.
Reference & Lookup
Default Router IP Finder
Default gateway address, username and password for 40+ router brands — plus how to find your own router’s IP on Windows, macOS, Linux, Android and iPhone.
Certification Comparison
CCNA, CCNP, CCIE, Network+, Security+, AWS and Azure compared on cost, exam code, difficulty, validity and salary range. Filter by level or vendor.
Practice & Exam Prep
OSI Model Quiz
20 questions on the seven layers, with an explanation after every answer. Instant scoring, and built for CCNA, Network+ and interview preparation.
Which Tool Should You Use?
| If you need to… | Use |
|---|---|
| Split a network into smaller subnets | Subnet Calculator |
| Design VLANs for departments and generate switch config | VLAN Calculator |
| Understand how a mask works bit by bit | IP to Binary Converter |
| Decide what internet plan to buy | Bandwidth Calculator |
| Work out whether your current speed is enough | WiFi Speed Test |
| Log in to a router you do not have the details for | Default Router IP Finder |
| Choose which certification to study next | Certification Comparison |
| Test what you actually remember | OSI Model Quiz |
Learn the Theory Behind the Tools
Every tool here has a matching guide. Start with networking fundamentals, then work through routing protocols, switching and VLANs, and network security. Preparing for an interview? Our top 50 networking interview questions covers what actually gets asked.