velxio
Emulate Arduino, ESP32 & Raspberry Pi. in your browser. Write code, compile, and run on 19 real boards: Arduino Uno, ESP32, ESP32-C3, Raspberry Pi Pico, Raspberry Pi 3, and more. No hardware, no cloud, no limits.. Discord: https://discord.gg/3mARjJrh4E
The Lens
By Erik Loyd, SaaS CEO and former COO/CFO of an AWS Premier Partner.
Updated Oct 2026
Velxio emulates microcontroller boards in your browser, so you can write, compile and run Arduino, ESP32 or Raspberry Pi Pico code against real CPU emulation before you own a board. Wire sensors on a canvas, watch the Serial Monitor, debug without frying anything. The code is AGPLv3 and velxio.dev has a free plan.
Self-hosting is one docker run of a prebuilt image, but that image covers only the Arduino, Pico and ESP32 families. STM32, Raspberry Pi Linux and partner boards like M5Stack stay on velxio.dev (licensed emulator binaries, big boot images).
That's the open core line. Free hosted caps ESP32 runs at an hour, gives STM32 and Pi Linux three 15-minute trials each, and keeps projects public. Paid plans unlock those boards and the desktop app: No AI $4/month, Maker $7, Pro $19, cheaper yearly. Students and solo makers: free. Anyone on STM32 or Pi: No AI covers it. Pro if you want Claude Code driving the canvas.
The catch: one maintainer writes nearly every commit, and the boards people pay for aren't in the open source image. Closed-source use needs a commercial license, price on request. Wokwi is the obvious hosted alternative; SimulIDE and Renode cover desktop.
Free vs Self-Hosted vs Paid
open coreFree: velxio.dev Free plan: 30+ boards (Arduino, ESP32, RP2040 including Pico W, RISC-V, M5Stack, XIAO), real CPU emulation, custom chips in C compiled to WASM, Library Manager with 100 MB storage, unlimited public projects, 20 daily AI credits (600/month cap). ESP32 runs are time-boxed to 1 hour per run; STM32, Raspberry Pi Linux and UNIHIKER get three 15-minute trial sessions per family.
Self-hosted: AGPLv3, one docker run of ghcr.io/davidmonterocrespo24/velxio. The image runs the Arduino/AVR, Raspberry Pi Pico and ESP32 (Xtensa and RISC-V) families. STM32, Raspberry Pi Linux, ESP32-C6 and partner boards are not in it. Using the code in a closed-source product, private SaaS, internal tool or white-label needs a Commercial License, price on request (indicative tiers: Startup up to 5 developers, Business up to 25, Enterprise unlimited). Contributors sign a CLA.
Paid: Hosted plans, month-to-month or annual: No AI $4/month or $36/year ($3/month), Maker $7/month or $69/year ($5.75/month), Pro $19/month or $189/year ($15.75/month). Every paid plan unlocks STM32 and Pi Linux with unlimited time, unlimited ESP32 run time, Velxio Desktop (offline, Linux/Windows/macOS), premium components, unlisted projects, .zip library uploads (500 MB) and 200 CI minutes/month. No AI has no AI features at all. Maker adds Agent and Tutor modes (500 daily AI credits). Pro adds private projects, connecting Claude Code or Codex over MCP, BOM and schematic export, GitHub Sync, 2 GB storage and 2,000 CI minutes.
Free for Arduino, Pico and ESP32 work, hosted or self-hosted. STM32, Raspberry Pi Linux and the desktop app start at $4/month or $36/year, and closed-source use of the code needs a separately negotiated commercial license.
What to do by team size
- Solo
- free; the hosted plan or one docker run
- Small team
- free for Arduino and ESP32; No AI at $4/month per account for STM32, Pi Linux and the desktop app
- Medium team
- self-host the AGPL image for Arduino/ESP32 classes, Maker or Pro accounts for the rest
- Large team
- commercial license, price on request, to embed or run it closed-source
Get tools like this every Wednesday
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A low score is not a verdict on quality. Young and niche tools start low by design. How we calculate scores
License: AGPL-3.0 + commercial
AGPLv3, or a paid commercial license (price on request) for closed-source use. Contributors sign a CLA.
Commercial use: ✓ Yes
About
- Owner
- David Montero Crespo (User)
- Stars
- 3,484
- Forks
- 362