Computing & Electronics Simulations
Two tools for the parts of computing that are hard to picture. Both are about binary — one at the scale of a 32-bit address, the other at the scale of a single wire — and both show you the bits rather than just the answer.
Two views of the same idea
Subnetting and logic gates look like separate subjects until you notice they are both about what a bit means in context. A subnet mask decides which of 32 bits name a network and which name a machine; a logic gate decides what one bit does to another. Borrowing a subnet bit doubles your networks for the same reason adding an input doubles a truth table — powers of two are the arithmetic underneath both.
Built for the exam and the job
These cover the ground a CCNA or CompTIA Network+ candidate needs on addressing, and the ground a first-year computer science or electronics course covers on combinational logic. Each page carries the formula, a worked example computed by the same code that runs the tool, and an honest list of what the model leaves out.
Nothing leaves your browser
Every address you type and every switch you flip is processed locally. There is no upload, no account and no server round trip, which also means the tools keep working on a laptop with no connection once the page has loaded. Share links carry the state in the URL, so you can hand someone an exact split or an exact circuit without either of you sending data anywhere.
Frequently asked questions
Is the subnet visualiser accurate enough to plan a real network with?
The arithmetic is exact — it is bit masking, and the page shows the operations it performs. What it will not do is check your block against the IANA special-purpose registry or your own addressing policy, and it does not handle variable-length subnetting in one pass. Treat it as a planning and teaching tool, and verify any split against your hardware before it goes live.
Can I build my own circuit in the logic gate simulator?
Not at the moment. It ships with eleven standard circuits, from single gates up to a full adder and a 2:1 multiplexer, chosen because they are the ones courses actually set. It is a tool for reading and understanding standard logic rather than a schematic editor, and the limitation is stated on the page rather than hidden.
Do these cover IPv6?
No. IPv6 uses the same prefix notation over 128 bits, but the host-count arithmetic and the network and broadcast conventions are different enough that presenting IPv4 results under an IPv6 label would be misleading. Rather than offer it half-right, the visualiser is IPv4 only and says so.