IoTSimulator
Built for people who want to learn, not just copy code. Every component has its own guide with wiring diagrams, pin explanations, and working examples. The simulator runs real AVR and RISC-V emulation, so the code you write here behaves the same way it would on a real board.
Wokwi
Made for people who already know what they are doing. If you need to test a custom library, simulate an obscure sensor, or debug bare-metal firmware, Wokwi gives you the tools. It supports Arduino C++, Rust, and MicroPython, and you can upload your own libraries as ZIP files.
Tinkercad Circuits
Designed for classrooms. The 3D view makes it easy to see how physical parts fit together, and the block-based coding mode helps younger students understand logic before dealing with syntax. It is owned by Autodesk and integrates with their broader Tinkercad ecosystem for 3D modeling.
How They Work
1. The Simulation Engine
Both IoTSimulator and Wokwi use real microcontroller emulators that run in the browser through WebAssembly. They simulate the CPU at the cycle level, so the same machine code that runs in the simulator would run identically on a real Arduino or ESP32. Under the hood, they use libraries like avr8js for AVR chips and rp2040js for RISC-V based boards. Tinkercad Circuits takes a different approach - it runs a simplified version of the code and focuses more on making the circuit simulation look realistic in 3D.
2. Libraries and Code Support
If you have used Arduino before, you know half the battle is getting the right library to work. Here is how each platform handles that:
- IoTSimulator comes with a curated set of libraries that are tested and documented. Each library has its own page that explains the methods, parameters, and gives you code examples you can copy directly into your sketch.
- Wokwi lets you pull in almost any library from the Arduino Library Manager. If that is not enough, you can upload your own as a ZIP file. This makes it the best choice for testing libraries before using them on real hardware.
- Tinkercad includes a fixed set of libraries (LiquidCrystal, Servo, IRremote, and a few others). You cannot add new ones, which limits what you can build.
3. WiFi and IoT Features
Both IoTSimulator and Wokwi can simulate WiFi on ESP32 chips. You can run a web server, connect to an MQTT broker, or send HTTP requests - all inside the simulator. Tinkercad does not support WiFi at all, so you cannot test any IoT project that needs network access.
Side by Side Comparison
| Metric | IoTSimulator | Wokwi | Tinkercad Circuits |
|---|---|---|---|
| Simulator Engine | Cycle-accurate WebAssembly (AVR/RISC-V) | Cycle-accurate WebAssembly (AVR/ARM/RISC-V) | Simplified code execution + analog matrix solver |
| Primary Target | Beginner-friendly guided curricula | Hardware prototyping & sandbox builds | Classroom STEM education & absolute basics |
| Visual Representation | Clean, flat 2D schematics with yellow highlight accents | Minimalist vector board/component outlines | Realistic pseudo-3D plastic models and breadboards |
| Documentation Integration | Deep: complete textbook guides & library method vaults on-screen | Standard markdown documentation pages | Guided tutorials embedded in lesson assignments |
| Programming Language | Arduino C++ | Arduino C++, Rust, MicroPython | Scratch-style blocks, Arduino C++ |
| Third-Party Libraries | Yes (Standard curated library list) | Yes (Unlimited registry + ZIP file uploads) | No (Restricted to pre-selected system list) |
| WiFi/IoT Emulation | Yes (Native ESP32 HTTP Server & Client) | Yes (via Wokwi gateway bridging) | No |
| Custom Components | No (Locked palette for standardized circuits) | Yes (Create custom JSON/JS logic devices) | No |
Note: Platform specs are compiled based on active documentation and release builds. Information is provided for evaluation purposes and is subject to updates by the respective service owners.
Which One Should You Use?
There is no single best simulator. The right choice depends on what you are trying to do:
Use IoTSimulator if:
You are learning electronics and want to understand how things work. Every component has a guide, every project has step-by-step instructions, and you can see the pin connections explained as you build.
Use Wokwi if:
You already know what you are doing and need to test custom code, try a library you have never used before, or debug something specific before putting it on real hardware. It supports more languages and lets you upload your own libraries.
Use Tinkercad if:
You are teaching a class and want students to see circuits in 3D before building them physically. The block coding mode helps absolute beginners understand logic before moving to text-based programming.