PICSimLab vs Wokwi: Desktop Offline Simulation or Browser-Based Simulation?
Verdict: Wokwi runs entirely in your browser — nothing to install, easy to share a project link, and strong for quick Arduino and ESP32 sketches. Its fuller features sit behind paid plans (paid plans from around €5.6/month, checked Oct 2026). PICSimLab is a free, open-source desktop application that works completely offline, simulates full development boards with attachable spare parts, and is the stronger free option for PIC microcontrollers in particular. PICSimLab also has an official online version, but it is limited compared with the desktop build (see below). Choose Wokwi for zero-install convenience and sharing; choose PICSimLab for offline PIC board work, MPLAB X debugging and no subscription.
At a glance
| Aspect | PICSimLab | Wokwi |
|---|---|---|
| Where it runs | Desktop application for Windows, Linux and macOS; works offline. An official online version exists (same source compiled with Emscripten) with documented limits — no Tools menu, no debugging and no serial communication except the IO Vterm terminal, and the fastest build runs at about 50% of desktop speed. | In the web browser. No installation; you need an internet connection to use it. |
| Price | Free and open source (GPL-2.0), desktop and online versions alike. | Free tier available; paid plans from around €5.6/month (checked Oct 2026) unlock the fuller feature set. |
| Microcontroller focus | PIC16F/PIC18F is the home turf, plus AVR/Arduino, STM32F103 (two boards only), ESP32 and ESP32-C3, and C51/Z80/STM8S103 — 21 simulated development boards in total. | Strongest around Arduino and ESP32-class boards and common components wired freely on a virtual canvas. |
| How you build | Choose a simulated board, load a compiled .hex file, attach spare parts (LCDs, keypads, sensors, motors, a basic two-channel oscilloscope). | Wire components and a board together in the browser editor and run the sketch there. |
| Debugging | Desktop version: MPLAB X integrated debugging for PIC/AVR and GDB paths for AVR, STM32 and ESP32. The online version has no debugging. | Browser-based debugging and monitoring features, with the fuller set on paid plans. |
| Sharing / classroom use | You share project/configuration files; everyone needs the desktop app (or the limited online version) to open them. | Share a link and the project opens in any modern browser — a genuine convenience for classes and forum answers. |
Where Wokwi is genuinely ahead
For a quick experiment — testing an Arduino or ESP32 idea, showing a teacher or a forum a working circuit, working from a machine where you cannot install software — Wokwi’s browser model is hard to beat. There is no installer, no operating-system differences, and a shared link reproduces your exact project on someone else’s screen. If most of your work is Arduino/ESP32 sketches and you value that sharing workflow, the paid tiers may be worth it to you.
Where PICSimLab is genuinely ahead
PICSimLab is free in full — no tier unlocks — and it works with no internet connection at all, which matters in labs, classrooms and countries where connectivity is metered. Its PIC support is the deeper of the two: real trainer boards such as McLab2 and PICGenios, the PIC16F877A project path (LED blink, HD44780 LCD, UART serial), and MPLAB X source-level debugging via the official plugin (plugin guide). Its Arduino and ESP32 boards are covered in our Arduino Uno and Nano and ESP32-DevKitC board pages.
About PICSimLab’s online version — honestly
PICSimLab does have an official online version, compiled from the same source with Emscripten. It is useful for a first look, but the official documentation is clear about its limits: no Tools menu, no debugging, no serial communication (only the IO Vterm virtual terminal), and the multithreaded build reaches about 50% of desktop speed and is only tested in desktop Chrome and Firefox. For anything beyond a quick test, the project itself advises the desktop version — download it free from our download page (files link to the official GitHub release). Our dedicated online version hub is now live – start there to try PICSimLab in your browser, and use the download page when you are ready for the full desktop version.
Which should you choose? By scenario
- Learning PIC microcontrollers (PIC16F877A, PIC18F4550) with MPLAB X: PICSimLab — this is its home ground, and it is free.
- Sharing a runnable Arduino/ESP32 demo by link: Wokwi.
- Unreliable or expensive internet, or an offline lab: PICSimLab desktop.
- A school Chromebook-style environment with no installs allowed: Wokwi, or PICSimLab’s online version for a limited first look.
- You resent subscriptions on principle: PICSimLab — there is nothing to subscribe to.
Wokwi has no affiliate programme and this page earns nothing from mentioning it; we recommend it above where the browser model genuinely fits better.
From simulation to real hardware
Both tools simulate boards that are cheap to own for real. When a project outgrows the simulator, the usual next steps are:
- An ESP32 development board — also available as a SparkFun ESP32 board (SparkFun originals) or a compact Seeed XIAO board for ESP32-C3 projects.
- An Arduino Uno for the ATmega328P sketches you prototyped in either simulator.
- An electronics starter kit with a breadboard, jumper wires and basic components to rebuild the simulated circuit physically.
- For budget buying outside the US/EU, the same ESP32 boards are listed on AliExpress and Banggood.
These hardware links are affiliate links routed through our /go/ redirects — see our affiliate disclosure. They never change the price you pay.