Draw on a snapped SVG canvas
Use select, line, bus, ferrite core, junction, text, rectangle, circle, loop-current, and arrow tools with grid dots or grid lines.
About CircuitSimpl
CircuitSimpl
Design circuits, control loops, and logic structures directly in your browser.
CircuitSimpl is a free browser-based diagram workspace for building clean electrical schematics, control-system blocks, logic gates, engineering labels, and export-ready circuit drawings. Place components, wire them together, tune labels and notation, design internal blocks when you need more detail, then export the result as a PNG or vector PDF.
Workspace Guide
Tooling guide.
The labelled screenshot guide will point at the live CircuitSimpl controls. For now, this preview follows the same guide structure as the other Simpl product pages and highlights example designs made in the editor.
100%
browser-based diagram creation for normal drawing and export workflows.
7
main component groups: Passive, Power, Semiconductors, Outputs, Switches, ICs, and Logic.
PNG/PDF
export routes for raster images and vector PDF diagrams.
Features
The circuit editor keeps drawing, symbols, labels, and export close together.
CircuitSimpl is built as a practical workbench for fast diagrams: a snapped canvas, a broad palette, direct editing controls, and exports that turn the current drawing into a shareable file.
Find components quickly
Switch between Basic and Advanced palettes, filter by All, ANSI, IEC, or CTRL, search components, and request missing parts from the palette.
Use a broad symbol set
Place passive parts, sources, grounds, power flags, diodes, transistors, outputs, switches, ICs, op amps, and logic gates.
Add engineering labels
Edit label and value text, use math notation, rotate labels, style text, and toggle pin or name labels when a diagram needs more context.
Design internals
Open nested workspaces inside op amps, powered op amps, ICs, and logic gates so a block can show its internal circuit detail.
Export polished diagrams
Download PNG or vector PDF outputs with export bounds, grid choices, background settings, component colors, and light or dark themes respected.
Privacy
Local diagramming by default. Cloud-backed only for feedback.
CircuitSimpl's ordinary drawing workflow happens in your browser. Creating diagrams, editing labels, changing the canvas, designing internals, and exporting files do not require an account.
Browser workspace
The editor stores the current drawing in page memory while you work and uses your browser to render SVG, PNG, and PDF exports.
Feedback submission
The request-component, review, and feature-request form is the cloud-backed path, using Firebase App Check and rate limiting to keep public feedback usable.
CircuitSimpl is a diagramming tool rather than a simulator: it helps you draw, label, structure, and export circuits and control diagrams without pretending to solve or verify the circuit behavior for you.
Component Library
CircuitSimpl symbols and control-diagram components.
The palette includes standard electrical schematic symbols, logic blocks, IC blocks, and control-system label shortcuts for building circuit diagrams and engineering diagrams in one canvas.
| Category | Component | Available symbols / variants |
|---|---|---|
| Passive | Resistor | Zigzag resistor, box resistor |
| Passive | Variable resistor | Zigzag variable resistor, box variable resistor |
| Passive | Capacitor | Non-polar capacitor, electrolytic capacitor |
| Passive | Inductor | IEC inductor, ANSI inductor, alternate ANSI inductor |
| Passive | Fuse | IEC fuse, ANSI fuse, alternate ANSI fuse |
| Power | Battery | Multi-cell battery, circular battery source symbol |
| Power | AC voltage source | AC voltage source symbol |
| Power | Current source | Current source symbol |
| Power | Dependent voltage source | Diamond dependent voltage source |
| Power | Dependent current source | Diamond dependent current source |
| Power | Ground | Line ground, triangle ground, earth ground, GND label ground |
| Power | Power flag | +5V flag, VCC flag, +VCC triangle flag |
| Semiconductors | Diode | Standard diode, Schottky diode, Zener diode, photodiode |
| Semiconductors | SCR | Silicon-controlled rectifier |
| Semiconductors | DIAC | DIAC trigger diode |
| Semiconductors | TRIAC | TRIAC bidirectional thyristor |
| Semiconductors | LED | Light-emitting diode |
| Semiconductors | Transistor | NPN, PNP, NMOS, NMOS enhancement, PMOS, PMOS enhancement, NJFET, PJFET |
| Outputs | Bulb | Lamp / bulb output symbol |
| Outputs | Motor | Motor output symbol |
| Switches | Push button | Momentary normally open push button, momentary normally closed push button |
| Switches | Lever switch | Normally open lever switch |
| Integrated Circuits | Op amp | Labelled op amp, plain op amp |
| Integrated Circuits | Powered op amp | Labelled powered op amp, plain powered op amp |
| Integrated Circuits | IC | Configurable integrated circuit block |
| Logic | AND gate | AND gate, NAND gate |
| Logic | OR gate | OR gate, NOR gate, XOR gate, XNOR gate |
| Logic | Buffer gate | Buffer gate, inverter / NOT gate |
| CTRL | Control-system shortcuts | Complex transfer function, summing junction, G(s), H(s), r(t), R(s), y(t), Y(s), c(t), C(s), b(t), B(s), e(t), E(s) |
Suggest a symbol
Missing a component, symbol, or notation shortcut? Send the request here and it will go to the same queue as the editor palette.