<metaname="description"content="Velxio is a free, open-source Arduino emulator that runs entirely in your browser. Real AVR8 emulation at 16 MHz, 48+ electronic components, Monaco Editor, Serial Monitor, and Library Manager — no cloud, no latency."/>
<metaproperty="og:title"content="Velxio — Free Local Arduino Emulator"/>
<metaproperty="og:description"content="Write, compile, and simulate Arduino sketches entirely in your browser. Real AVR8 CPU at 16 MHz, 48+ electronic components, Serial Monitor, and Library Manager. Free & open source."/>
<metaname="twitter:title"content="Velxio — Free Local Arduino Emulator"/>
<metaname="twitter:description"content="Write, compile, and simulate Arduino sketches entirely in your browser. Real AVR8 CPU at 16 MHz, 48+ components, Serial Monitor, Library Manager. Free & open source."/>
"description": "Free, open-source Arduino emulator running entirely in the browser. Features real ATmega328p (AVR8) emulation at 16 MHz, RP2040 emulation, 48+ interactive electronic components, Monaco Editor, Serial Monitor with baud-rate detection, arduino-cli compilation backend, and Library Manager.",
"description": "Velxio is a free, open-source Arduino emulator. Real AVR8 CPU emulation, 48+ components, Monaco Editor, Serial Monitor — no cloud, no latency.",
"text": "Yes, Velxio is completely free and open source under the MIT License."
}
},
{
"@type": "Question",
"name": "Does Velxio work offline?",
"acceptedAnswer": {
"@type": "Answer",
"text": "Velxio can be self-hosted via Docker. Once running, the simulation engine works fully offline in the browser. Compilation requires the local arduino-cli backend."
}
},
{
"@type": "Question",
"name": "What boards does Velxio support?",
"acceptedAnswer": {
"@type": "Answer",
"text": "Velxio supports Arduino Uno (ATmega328p) with full AVR8 emulation and Raspberry Pi Pico (RP2040) emulation. More boards are planned."
}
},
{
"@type": "Question",
"name": "Is Velxio a Wokwi alternative?",
"acceptedAnswer": {
"@type": "Answer",
"text": "Yes. Velxio is a free, self-hosted alternative to Wokwi. It uses the same avr8js and wokwi-elements open-source libraries but runs entirely on your machine with no cloud dependency."
<h2>The free, open-source Arduino emulator that runs in your browser</h2>
<p>Write Arduino code, compile it, and simulate it with real AVR8 CPU emulation and 48+ interactive electronic components — all running locally in your browser. No cloud, no latency, no account required.</p>
<h3>Features</h3>
<ul>
<li>Real ATmega328p (AVR8) emulation at 16 MHz via avr8js</li>
<li>Raspberry Pi Pico (RP2040) emulation via rp2040js</li>
<dd>Yes. Velxio is free and open-source under the GNU AGPLv3 license. A commercial license is available for proprietary integrations.</dd>
<dt>Does Velxio work offline?</dt>
<dd>The simulation engine runs entirely in the browser. Compilation requires the local arduino-cli backend. Self-hosted deployments work fully offline once running.</dd>
<dt>Is Velxio a Wokwi alternative?</dt>
<dd>Yes. Velxio is a free, self-hosted alternative to Wokwi. It uses the same avr8js and wokwi-elements open-source libraries but runs on your own machine.</dd>
<dd>Arduino Uno (ATmega328p / AVR8), Arduino Nano, Arduino Mega 2560, Raspberry Pi Pico (RP2040), ESP32-C3 (RISC-V), and more. 17 boards in total.</dd>
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<section>
<h2>Free Online Arduino Simulator</h2>
<p>Velxio is a free online Arduino simulator with real AVR8 emulation at 16 MHz. Simulate Arduino code with 48+ interactive electronic components directly in your browser — no install, no account required. <ahref="/arduino-simulator">Open Arduino Simulator →</a></p>
<ul>
<li>Arduino Uno (ATmega328P) simulation at 16 MHz</li>
<li>Serial Monitor with auto baud-rate detection</li>
<li>Multi-file sketch support (.ino, .h, .cpp)</li>
<li>Free and open-source (GNU AGPLv3)</li>
</ul>
</section>
<section>
<h2>Arduino Emulator — Real AVR8 & RP2040 Emulation</h2>
<p>Velxio is a cycle-accurate Arduino emulator built on avr8js and rp2040js. Every AVR opcode is faithfully emulated at 16 MHz — the same silicon behavior as real hardware. <ahref="/arduino-emulator">Open Arduino Emulator →</a></p>
<ul>
<li>All 135 AVR8 instructions emulated</li>
<li>Hardware timers (Timer0/1/2) with PWM, CTC, and overflow interrupts</li>
<li>10-bit ADC, full USART0 (TX/RX), SPI, I2C</li>
<li>RP2040 dual-core ARM Cortex-M0+ via rp2040js</li>
<li>RISC-V RV32IMC (ESP32-C3) emulation in browser</li>
</ul>
</section>
<section>
<h2>ATmega328P Simulator</h2>
<p>Simulate ATmega328P firmware exactly as it runs on Arduino Uno and Nano. Full AVR8 emulation: PORTB, PORTC, PORTD, Timer0/1/2, ADC, USART0, and all interrupt vectors. <ahref="/atmega328p-simulator">Open ATmega328P Simulator →</a></p>
<li>Timer0 (8-bit), Timer1 (16-bit), Timer2 (8-bit) — all PWM modes</li>
<li>10-bit ADC, 6 analog channels (A0–A5)</li>
<li>USART0 with configurable baud rate</li>
</ul>
</section>
<section>
<h2>Arduino Mega 2560 Simulator</h2>
<p>Simulate Arduino Mega 2560 (ATmega2560) code for free. 256 KB flash, 54 digital pins, 16 analog inputs, 4 hardware serial ports (Serial, Serial1, Serial2, Serial3), and 6 hardware timers. <ahref="/arduino-mega-simulator">Open Mega 2560 Simulator →</a></p>
