Build. Simulate. Understand.
Advanced Digital Logic
and Computing Lab
A browser-native environment for designing, simulating, and understanding digital logic circuits — from basic gates to flip-flops, MSI components, and multi-language code export.
What's inside
Everything you need
to think in logic
A complete toolbox for digital logic design — built entirely in the browser with zero installs, zero servers, and zero friction.
Real-Time Simulation
Every wire updates instantly as you toggle inputs. Signal colours (green = HIGH, red = LOW) flow through the circuit with zero lag — powered by a topological-sort engine that detects combinational loops.
IEEE Gate Shapes
Proper IEEE/ANSI gate symbols drawn on canvas — AND, OR, NOT, NAND, NOR, XOR, XNOR, BUFFER — with correct negation bubbles and bezier input stubs. Not rectangles with labels.
Flip-Flops & Sequential Logic
SR, D, JK and T flip-flops with proper rising-edge clocking, Q / Q̄ outputs, and internal state. Build a 2-bit counter or 4-bit shift register in one click — connect a Clock gate to watch them run.
MSI Components
High-level building blocks: MUX 2:1 / 4:1, DEMUX 1:2, 2-to-4 & 3-to-8 Decoders, 4-to-2 Encoder, Priority Encoder, Comparator, Half Adder, Full Adder, and a live Binary-to-Hex display.
6-Language Code Export
Export your circuit as executable JSON, Python, C, C++, Verilog, or VHDL. The code panel live-syncs as you build — copy it straight into your project or simulator.
Circuit Validator
Built-in rule checker flags unconnected pins, floating outputs, and invalid gate configurations — highlighted inline with error badges, no console hunting required.
Waveform Viewer
A full timing-diagram panel with recording, step mode, edge markers (↑↓), bus grouping with hex readout, zoom, and a pattern generator for automated input sequences.
Truth Table Generator
Select any gate to see its truth table instantly. For a complete circuit with up to 6 inputs the full circuit truth table is generated and also embedded in exported PNG images.
Save, Load & Templates
Named circuit saves with descriptions, per-user storage, and a growing library of built-in templates: Half Adder, Full Adder, 2:1 MUX, 2-to-4 Decoder, Comparator, Priority Encoder, 2-bit Counter, and 4-bit Shift Register.
Gate Library
Every gate you'll ever need
Basic Gates
AND
OR
NOT
NAND
NOR
XOR
XNOR
BUFFER
Flip-Flops
SRSR Flip-Flop
DD Flip-Flop
JKJK Flip-Flop
TT Flip-Flop
MSI Components
MUX2:1 / 4:1 Multiplexer
DMUX1:2 Demultiplexer
DEC2-to-4 / 3-to-8 Decoder
ENC4-to-2 Encoder
HADDHalf Adder
FADDFull Adder
CMP1-bit Comparator
HEXBinary → Hex Display
Sequential Templates
CNT2-bit Counter (T-FF)
SHF4-bit Shift Register (D-FF)
Code Export
Your circuit.
Any language.
The code panel live-syncs as you build. Export your circuit to six languages — ready to paste into a real project or HDL simulator.
// Gateonix Circuit — Verilog // Gates: 6 | Wires: 6 module circuit ( input wire a, input wire b, output wire sum, output wire carry ); wire w3; wire w4; assign w3 = a ^ b; assign w4 = a & b; assign sum = w3; assign carry = w4; endmodule
Under the Hood
Zero dependencies.
Pure browser tech.
Gateonix is written in vanilla HTML, CSS, and JavaScript — no framework, no build step, no install. Just open and build.
Canvas 2D API
All gate shapes, wires, pins, and the minimap are drawn directly on an HTML Canvas — IEEE shapes with custom bezier curves.
Topological Sort
Kahn's algorithm evaluates gates in dependency order every tick. Combinational loops are detected and highlighted in real time.
Web Crypto API
User passwords are hashed with SHA-256 via the native crypto.subtle API before being stored in localStorage — never in plaintext.
localStorage
Circuits, user templates, and accounts persist locally in the browser — no backend, no account required beyond your own device.
jsPDF + SVG Export
One-click export to PNG (2× resolution with truth table), SVG vector, or PDF — circuit name, date stamp, and watermark included.
JetBrains Mono + Syne
Two complementary typefaces: Syne for display headings and UI chrome, JetBrains Mono for all signal values, code, and data labels.
Start building circuits
right now
No install. No sign-up required. Just open and drag.