Arduino simulators, compared honestly
Or see every lesson.
- 505parts on the bench
- 45boards running now
- 1.00xreal time, on every board
For a free Arduino simulator in the browser, most people choose between three: Tinkercad Circuits for young beginners who need block coding, Wokwi for maker projects across many ESP32 chips, and Mokxi for classes and for circuits where analog parts meet real firmware. The table below compares them; the rest of the page covers eleven more.
There is no single best Arduino simulator, because "simulator" covers four different jobs: running your sketch on a modeled chip, drawing a circuit, designing digital logic from gates up, and SPICE analysis. Most disappointment comes from picking one built for another job.
This page compares fourteen current tools on that basis: every tool has real strengths, and the honest answer for several of the questions below is a tool that is not Mokxi. Each tool has a full page of its own, with the sources its facts came from and the month they were last checked.
What to check before picking one
Five questions cover most of what matters. Does it run your code or only draw a circuit? Does it need an install or account? What does free include? Does it model analog behavior deeply enough for the job? And for a school, can a teacher assign a starter, see progress, check work and return feedback without stitching several tools together? The tools below answer those questions differently enough that the right pick depends on the class or project in front of you.
The three browser simulators most people choose between
| Mokxi | Wokwi | Tinkercad Circuits | |
|---|---|---|---|
| Best for | Teacher-led electronics classes, and circuits where analog parts and firmware meet | Maker projects and firmware work across many ESP32 chips | Young beginners, with block coding and 3D design next door |
| Run a circuit without an account | Yes | Yes | Public designs and lessons can be browsed; building needs an account |
| Boards | 42 that compile your sketch in the tab, with no build server: Arduino, ESP32, ESP8266, Raspberry Pi Pico, STM32, micro:bit and ATtiny85 | AVR Arduino boards and the ATtiny85, ten ESP32 chips, STM32 and the Raspberry Pi Pico | The Arduino Uno, the micro:bit and the ATtiny |
| Languages | Arduino C++; MicroPython on the Pico and the classic ESP32 boards; CircuitPython on the Pico | Arduino, ESP-IDF, MicroPython, CircuitPython on the ESP32, and Rust | Blocks and text |
| Analog circuits | Solved with real device models beside the firmware; SPICE decks run in the editor | Digital simulation; simulating a resistor divider is an open feature request | Basic parts such as resistors and LEDs beside the Uno |
| Classes | Roster, starter projects, checks, submissions, feedback and a gradebook export | A Classroom license, priced by quote | Class codes, teacher moderation and student designs, free |
| Price | A free plan with every board and part; paid plans add private projects, sending a sketch to a real board and classes | A free Community plan; paid Hobby, Hobby+ and Pro plans | Free |
Tinkercad Circuits
Free, from Autodesk, browser-based, and the most widely used classroom circuit tool by a wide margin, with a large, beginner-friendly component library and both block-based and text coding for the Arduino Uno and the micro:bit. It is a strong first tool for a classroom or a total beginner, and a weaker fit once a project needs a board it does not model, such as an ESP32, timer-level firmware accuracy, or a breadboard at real component pitch.
Mokxi
Free to use with no account required, browser-based, and built around running your actual C++ on a modeled chip rather than an approximation of it: 42 boards, from the Arduino Uno to ESP32, ESP8266, Raspberry Pi Pico, STM32 and micro:bit boards, compiled and run in the tab, plus the Raspberry Pi computers for Python, with 505 parts on a real 0.1 inch breadboard. SPICE decks run in the editor on an engine checked against ngspice, a logic path goes from one NAND gate to a small computer, and classes add starters, checks and submissions. WiFi is simulated, and reaches the real internet once you sign in. Mokxi does not model Bluetooth or PCB layout, is not open source, and its SPICE runner has no BSIM models, Monte Carlo or distortion analysis.
Wokwi
Browser-based and built for running embedded projects, Wokwi has the broadest range of ESP32 chips in this group, with Arduino, STM32, Pico and ATtiny85 support as well. Its official tools include simulated WiFi that reaches the real internet, MQTT, an eight-channel logic analyzer, GDB debugging and custom chips, and it runs MicroPython, ESP-IDF and Rust as well as Arduino code. The free Community plan covers public projects and any library in the Arduino Library Manager; VS Code integration, CI and private projects come with its paid plans. It is a strong answer for an individual project that needs those parts or tools. Mokxi is the stronger fit when the circuit has analog parts that must behave like the real ones, when builds should run in the browser with no build minutes, or when the simulator has to sit inside a class roster, starter-project, checking and submission workflow.
Proteus
A commercial, paid Windows desktop tool from Labcenter Electronics, long established in embedded engineering education and industry. Its VSM feature genuinely runs compiled microcontroller firmware against SPICE-based analog circuitry in the same schematic, across more than 750 microprocessor variants by Labcenter’s count, and it includes full PCB design tools most simulators on this list do not attempt at all. A free demo runs its sample designs. It suits a curriculum or a professional workflow better than a first project.
Fritzing
Open source, and mainly a breadboard, schematic and PCB layout tool for documenting and designing a circuit, with ordering through Fritzing Fab. It also has a simulator built on ngspice for the DC and transient behavior of circuits whose parts carry SPICE models, but it does not run microcontroller code. The source is free, and the official installers are sold for a one-time contribution. It is a strong choice for drawing up a build to share or to fabricate, and the wrong tool for watching code and hardware behave together.
SimulIDE
Free, open source under the AGPLv3, and a desktop application for Windows, Linux and macOS rather than a browser tool, built around simulating PIC, AVR and Arduino microcontrollers alongside mixed analog and digital parts, with its own code editor and debugger. It has no account and no cloud dependency, at the cost of needing an install, which a browser tool does not.
Falstad (CircuitJS)
Free, open source, and built by Paul Falstad as a general electronics teaching tool: real-time analog and digital circuit simulation with live current and voltage animation, in the browser or as standalone offline builds. Its main simulator does not compile and run microcontroller firmware; a separate AVR8js demo page runs a small Arduino sketch against a circuit. That makes it an excellent tool for the electronics half of a project and a limited one for the firmware half.
Multisim
A commercial, paid SPICE simulation tool from NI, widely used in university electrical engineering courses and high school digital electronics, with virtual instruments (an oscilloscope, a function generator, a multimeter) alongside its schematic capture and analysis. Its browser version, Multisim Live, closed on September 15, 2026, and the desktop version runs on Windows. It is aimed at analog and mixed-signal circuit analysis rather than at an Arduino project with a breadboard and a sketch; student and paid editions both exist, so check its current licensing directly.
LTspice
A free SPICE simulator from Analog Devices for Windows and macOS, with schematic capture, a waveform viewer and a large library of manufacturers’ models, and no artificial limits on circuit size. It is one of the most widely used SPICE programs in industry and college courses. It does not run microcontroller firmware, and it has no browser or ChromeOS version.
Qucs-S
A free, open-source desktop program for Linux, Windows, macOS and FreeBSD that puts one schematic interface over several engines: ngspice, Xyce, SpiceOpus, and Qucsator for RF and microwave work. It covers analyses Mokxi does not, such as S-parameters, harmonic balance and distortion. It is a circuit simulator, not a microcontroller one.
EveryCircuit
A circuit simulator for the web, Android and iOS, known for animating voltage, current and charge as a circuit runs, with analog and digital parts in one circuit and a large public gallery. It is free to explore, and building your own circuits past five components needs a paid upgrade. A class license exists for courses. It does not run Arduino sketches.
Logic simulators: Logisim-evolution, Digital and CircuitVerse
Three free, open-source tools built for digital logic rather than for microcontrollers. Logisim-evolution is a desktop app for Windows, macOS and Linux with subcircuits, a chronogram, TTL chips, VHDL components and FPGA board support. Digital, by Helmut Neemann, is a Java desktop program with test cases stored in the circuit, VHDL and Verilog, and FPGA export. CircuitVerse runs in the browser, with groups, assignments with deadlines and grading, and LMS links through LTI. Mokxi overlaps with all three on gates, flip-flops and custom chips, and adds breadboard logic chips, analog parts and microcontrollers; it has no HDL or FPGA support.
Boards and chips, briefly
Tinkercad Circuits centers on the Arduino Uno and the micro:bit, and SimulIDE on PIC, AVR and Arduino. Mokxi models 45 boards across AVR, ESP32, ESP8266, RP2040, STM32, micro:bit and Pi, and Wokwi covers the widest range of ESP32 chips. Proteus supports a wide range of microcontroller families through its VSM libraries. Fritzing draws any board but does not run its code, and Falstad, Multisim, LTspice, Qucs-S and EveryCircuit simulate a circuit’s electronics rather than a chip’s firmware. The logic simulators work from gates up and have no microcontroller boards.
Open this circuit in the editor. Arduino Uno: blink, wired as it runs at the top of this page. Change a part or a value and run it again.
Questions
Which of these actually runs my Arduino sketch?
Tinkercad Circuits, Wokwi, Mokxi, SimulIDE and Proteus (through VSM) all run real or Arduino-compatible firmware against a modeled chip, and Falstad has a separate AVR8js demo page. Fritzing, Multisim, LTspice, Qucs-S and EveryCircuit simulate circuits without running a sketch, and the logic simulators work from gates up.
Which of these is free?
Tinkercad Circuits, Mokxi, SimulIDE, Falstad, LTspice, Qucs-S, Logisim-evolution, Digital and CircuitVerse are free to use, and Wokwi has a free Community plan. Fritzing’s source is free and its installers are sold for a contribution, EveryCircuit limits free circuits to five components, and Proteus and Multisim are commercial products; check each vendor’s current pricing directly, since it changes.
Which one should a total beginner start with?
Tinkercad Circuits for the gentlest on-ramp and the largest classroom install base, or Mokxi for a first project that already involves real C++ and a specific board like an Uno or an ESP32.
Which one should I use for serious analog circuit design?
LTspice, Qucs-S, Proteus or Multisim, all SPICE-based tools built for that job. Mokxi runs SPICE decks on an engine checked against ngspice, but it has no vendor model libraries, distortion or Monte Carlo analysis, and it says so plainly on its own pages.
Which one needs no install at all?
Tinkercad Circuits, Wokwi, Mokxi, Falstad (CircuitJS), CircuitVerse and EveryCircuit’s web version run in a browser tab. Proteus, Fritzing, SimulIDE, Multisim, LTspice, Qucs-S, Logisim-evolution and Digital are desktop applications that need a download and an install first.
Keep going
Build this for real
Open the editor, change a value and watch the number move with it. Nothing to install, and no account needed.