Source: https://mokxi.com/vs/proteus Updated: 2026-09-27 Comparison # Mokxi and Proteus, compared fairly Mokxi is a free Proteus alternative for microcontroller simulation. It runs Arduino, ESP32, Pico and STM32 sketches against a circuit in your browser, with nothing to install and no license. Proteus is a commercial, paid tool from Labcenter Electronics with a SPICE-accurate analog simulator, a firmware-running VSM feature and full PCB design, aimed at embedded engineering education and professional work. Mokxi is a free, browser-based firmware simulator with a real breadboard. Here is where each one is the right answer. or see the plans - 192 parts on the bench - 25 boards running now - 1.00x real time, on every board Click to open it in the editor Running here on our own RISC-V core, on the machine in front of you. The Mokxi editor running an Arduino Uno weather station, with the LCD showing the reading and the serial monitor printing it live. ## Where Proteus leads These are the strongest reasons to choose Proteus today. - VSM genuinely combines SPICE-accurate analog simulation with real microcontroller firmware execution in the same schematic, across a wide range of chip families. - Full schematic capture and PCB layout in the same product, carrying a design from a breadboard idea through to a board you can send for fabrication. - Long established in embedded engineering courses and professional workflows, with the depth of analog modeling that a serious analog design needs. - Supports a far wider range of microcontroller families than an Arduino Uno or an ESP32-C3. ## Where Mokxi leads These are working parts of Mokxi you can open and test for yourself. - Free, with no license to buy, and running entirely in a browser tab with nothing to install. - A real breadboard on a 0.1 inch grid rather than a schematic-first workflow, which suits wiring a project the way a beginner or a maker actually builds one. - Your C++ is built by a real clang and the firmware runs on a cycle-accurate ATmega328P or RISC-V core, in the tab, with no license dongle or install step. - No PCB design at all: Mokxi stops at the breadboard and the firmware. ## Side by side Checked on 2026-09-16. If anything here has gone stale, that is our mistake and we want to know. Mokxi Proteus Aimed at Makers and firmware work Embedded engineering and PCB design Price Free Paid, commercial license Runs in A browser tab A Windows desktop install Analog depth Nodal analysis on the canvas; a SPICE engine for decks, checked against ngspice SPICE-accurate (VSM) PCB design No Yes ## Which one should you use Straight answers. Where the other one is the right call, we say so. ### You need a free tool to try a sketch in a browser tab today Mokxi. ### You are doing serious analog design or need SPICE accuracy Proteus, not Mokxi. ### You need to take a design through to a fabricated PCB Proteus. Mokxi has no PCB tools at all. ### You want an ESP32-C3 with no license to buy Mokxi. ## Looking for a free Proteus alternative? Most people who search for one want to run a microcontroller sketch against a circuit without a Proteus license: an Arduino course, a student project, a first go at an ESP32. For that job Mokxi is free, runs in a browser tab with nothing to install, and compiles the sketch in the page. For the other things Proteus is bought for, it is not a replacement. Mokxi’s SPICE engine has no vendor model libraries or BSIM MOSFETs, Mokxi has no PCB layout, and it does not cover Proteus’s range of chip families. If your course or your work depends on those, stay with Proteus. ## Compare the other options The same straight comparison for the tools teachers, students and makers also consider. Mokxi vs Tinkercad Circuits Mokxi vs Wokwi Mokxi vs Fritzing Mokxi vs SimulIDE Mokxi vs Falstad (CircuitJS) Mokxi vs Multisim Mokxi vs LTspice Compare every simulator ## In short Is there a free alternative to Proteus for Arduino simulation? Yes. Mokxi simulates the Arduino Uno, Nano, Mega, Leonardo and Uno R4, among other boards, on its free plan, running the compiled sketch in your browser. Should I use Mokxi if you need a free tool to try a sketch in a browser tab today? Mokxi. Should I use Mokxi if you are doing serious analog design or need spice accuracy? Proteus, not Mokxi. Should I use Mokxi if you need to take a design through to a fabricated pcb? Proteus. Mokxi has no PCB tools at all. Should I use Mokxi if you want an esp32-c3 with no license to buy? Mokxi. ## Try it yourself A comparison page is somebody else’s opinion. Open the editor, press Run and make up your own mind. Start building Open the editor