TinkerSim
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Analog · Digital · MCU Coming Soon

Build circuits.
Simulate reality.

Drag-and-drop circuit design with real SPICE physics and boolean logic propagation — all in your browser. No installs, no setup. Microcontroller simulation coming soon.

Start simulating freeOpen the app
ngspice-wasm PoweredBoolean Logic EngineArduino Support Coming SoonNo Installation RequiredWork Autosaved
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Simulating

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Simulation Engines

Three simulators.
One canvas.

Mix analog, digital, and microcontroller components freely. Each engine detects what it should run and fires automatically.

Analog SPICE Simulation
Real DC operating point and transient analysis powered by ngspice-wasm. Accurate voltage drops, current flows, and capacitor dynamics — the same physics as professional EDA tools.
BatteryResistorCapacitorLEDDiodeSwitchPotentiometerBuzzer
Digital Logic Design
Boolean propagation engine using topological sort — logic states ripple through your circuit instantly. Build combinational logic and watch outputs update in real-time.
ANDORNOTXORNANDNORLogic InputLogic Output
In Development
Arduino Programming
Write C++, compile to AVR firmware, and watch it run directly in the browser — no physical board needed. Full digital I/O, timers, and a serial monitor with bidirectional coupling to the circuit canvas. Currently in development.
Arduino UnoC++ EditorAssembly ViewSerial MonitorPin States

Coverage

Know before
you build.

TinkerSim is a focused simulator, not a full SPICE suite. Here's exactly what works, what doesn't, and where you'll hit limits — so you don't waste time wiring the unsupported.

Analog — SPICE Enginengspice-wasm
DC operating point (.op)Voltages & currents at steady state
Transient analysis (.tran)Time-domain simulation with configurable step/stop
Resistors, capacitors, LEDs, diodes
Switch, pushbutton, potentiometer, buzzer
Ideal voltage source (battery)V-source only — no current-source primitive yet
AC / frequency analysis (.ac)Bode plots, impedance sweeps
BJT, MOSFET, op-amp modelsNo semiconductor device models in this release
Inductor / transformer
Floating nodesEvery net must connect to ground — open nodes cause SPICE to fail with a singular matrix error
Short circuitsA direct battery short will diverge; add at least a small series resistor
Digital — Boolean EngineKahn BFS
AND, OR, NOT, XOR, NAND, NOR
Logic Input (toggle HIGH / LOW)
Logic Output (indicator)
Combinational logic (fan-out, multi-gate chains)
Propagation delay / timingAll logic is zero-delay combinational — no clock or timing model
Sequential logic (flip-flops, latches)No memory elements; feedback loops are detected as cycles and ignored
Tri-state / open-collector outputs
Combinational feedback loopsCycle detection fires — the affected loop output is left undefined rather than latch-ing
Mixed-SignalCoupling
Analog + digital on the same canvasBoth engines run independently when their respective components are present
Signal coupling between enginesA logic gate output cannot drive a SPICE node and vice versa — the two engines do not exchange values
Analog-to-digital or DAC conversion
Simulation caveats
Circuit size

No hard cap, but ngspice-wasm is single-threaded. Circuits with more than ~50 nodes may take several seconds to converge on transient runs.

Convergence failures

Highly non-linear circuits (many diodes in series, very stiff sources) can fail to converge. The simulator will surface the SPICE error in the inspector panel.

Ground reference

SPICE requires exactly one node connected to ground (GND pin on the battery). Circuits without a ground node will not simulate.

Need pin layouts and SPICE model notes? View the full component reference →

Live Examples

Try a circuit
in one click.

Pre-built circuits that open directly in the simulator. No account needed — just click and explore.

SPICE
LED + Current-Limiting Resistor
The most fundamental analog circuit. Measures actual forward voltage across the LED and current through the branch.
Battery 9VResistor 470ΩLED
Open in simulator
SPICE
Voltage Divider
Two equal resistors split 9V to 4.5V at the midpoint. Probe the middle node to verify Ohm's law.
Battery 9VResistor 10kΩResistor 10kΩ
Open in simulator
Boolean
Half-Adder
XOR computes the sum bit; AND computes the carry. Toggle the logic inputs and watch both outputs update instantly.
Logic Input ×2XOR GateAND GateLogic Output ×2
Open in simulator
SPICE
Switch-Controlled LED
Open the switch and the LED goes dark; close it and current flows. DC operating point updates on every toggle.
Battery 9VSwitchResistor 330ΩLED
Open in simulator

Who It's For

Built for anyone
who tinkers.

Whether you're learning Ohm's law for the first time or prototyping a circuit before ordering parts, TinkerSim meets you where you are.

Students & Learners

Visualise circuit theory without buying hardware. Build the same circuits your textbook describes and see real voltage and current values instantly.

Hobbyists & Makers

Prototype and validate ideas before ordering parts. Catch wiring mistakes and measure expected voltages before a single component is soldered.

Educators

Build a circuit, click Share, and paste the URL into your slides. Students open it in any browser and interact with the same circuit — no accounts, no installs.

Workflow

From idea to simulation
in four steps.

01

Pick your components

Drag resistors, capacitors, LEDs, logic gates, and more from the palette onto the canvas.

02

Connect with wires

Click a component pin and drag to another to connect them. Wires route automatically between nodes.

03

Hit Run

TinkerSim detects your circuit type and fires the right engine. Voltages, currents, and logic states update instantly.

04

Share the URL

Click the Share button to copy a link that encodes your entire circuit. Anyone with the link can open and run it — no account needed.

Roadmap

Where we are.
Where we're going.

TinkerSim is actively developed. Here's the current state and what's coming next.

Complete

Analog SPICE Simulation

DC operating point and transient analysis. Voltage, current, and capacitor dynamics — the same physics as professional EDA tools.

BatteryResistorCapacitorLEDDiodeSwitchPotentiometerBuzzer
Complete

Digital Logic Gates

Boolean propagation engine with topological sort. Full gate library with real-time output.

ANDORNOTXORNANDNORLogic I/O
Complete

Accounts & Projects

Multi-project workspace with Firestore sync, URL sharing, and org-based access control.

AuthProjectsURL SharingFirestore
In Development

Arduino Simulation

Write C++, compile to AVR firmware in the browser, and run it against the circuit canvas. Serial monitor included.

Arduino UnoC++ EditorPin StatesSerial Monitor
Planned

ESP32 & More Boards

Extend MCU simulation to ESP32 (Xtensa) and additional microcontroller families.

ESP32Xtensa

+6 more planned features

View full roadmap

Ready to start tinkering?

Free to use. No credit card. No install. Open the browser and build.

Create free account

Autosaved every 3 seconds

Signed-in projects sync to the cloud in real time. Anonymous sessions persist in browser storage — sign in to keep work across devices.

Auth & data secured

Authentication via Clerk. Circuit data stored in Firebase Firestore with per-user isolation. All traffic over HTTPS. Security details →

Chrome, Firefox, and Edge

The SPICE engine runs as WebAssembly — it requires a modern, evergreen browser. Safari is not currently supported due to WASM thread limitations.

Delete your data any time

You own your circuits. Delete individual projects from the app, or delete your account and all associated data from the account settings.

Requires internet

TinkerSim is not an offline app. An active connection is needed to load the simulation engine and sync projects. Offline mode is not currently supported.

Beta