free breadboard simulator
A breadboard simulator that runs right here.
No download, no account, no credit card. This is a live one — the LED below is being simulated as you read.
simulating…
What the TinyOhms Workbench does
- Real parts. Battery packs (3, 4.5, 9 V), resistors with colour bands, potentiometers, capacitors, LEDs, a 1N4001 diode, switches, buttons, active buzzer, piezo, DC motor, light sensor, thermistor, an NPN transistor, and 555 and 4017 chips.
- Live current flow. Chevrons show which way current goes and how much; inspect mode prints the voltage at every hole and the current through every part.
- Things break. Push an LED past 30 mA and it pops. Short the battery and you get the warning a real one would give you as heat.
- Sound and scope. Buzzers sound, and capacitor and 555 circuits draw their waveforms on a scope.
- An engine you can trust. The solver is cross-checked against ngspice — the professional SPICE simulator — on every project on this site, within 3 %.
- Save and share. Sign in with an email code to keep circuits; any circuit can be shared as a link that opens straight on the bench, or in the iPhone and iPad app.
What it doesn't do
It does not simulate Arduino code or draw schematics. If you need those, the comparisons below point you to tools that do. TinyOhms is for the analog and logic circuits you build before code — and for understanding them, which is why every project comes with the math.
Other free simulators worth knowing
- Tinkercad Circuits (Autodesk, browser, free with an account): breadboard view plus Arduino code simulation. Compared with TinyOhms →
- EveryCircuit (browser and mobile, free up to 5 parts, US$15 unlock): animated schematics with a big community library. Compared with TinyOhms →
- Falstad CircuitJS (browser, free, open source): a schematic simulator with animated current — excellent once you read symbols.
- Wokwi (browser, free tier): microcontroller simulation for Arduino, ESP32 and Raspberry Pi Pico code.
Descriptions of other tools reflect their public sites as of September 2026. Their names belong to their owners, none of whom are affiliated with TinyOhms.
Start with a project
Never built a circuit? Start here, then open First Light — the same loop as the board above, explained from zero. When something doesn't work, the troubleshooting pages run the broken circuit next to the fix.