Velxio
The most recommended of 12 firmware emulators
Browser-based emulator for Arduino, ESP32 and Raspberry Pi boards that runs with no setup, so projects can be tested without physical hardware. Critics say it takes away learning.
Browser-based emulator for Arduino, ESP32 and Raspberry Pi boards that runs with no setup, so projects can be tested without physical hardware. Critics say it takes away learning.
24 people gave an opinion
- recommend it
- 21
- criticize it
- 3
- approval share
- 88%
Recommended in 3 of 13 months
- November 2025: not recommended
- December 2025: not recommended
- January 2026: not recommended
- February 2026: not recommended
- March 2026: recommended
- April 2026: not recommended
- May 2026: not recommended
- June 2026: recommended
- July 2026: not recommended
- August 2026: not recommended
- September 2026: not recommended
- October 2026: recommended
- November 2026: not recommended (month in progress)
Why it doesn’t carry the badge
- 21 people recommend itNeeds 10 or more, met.
- 7 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 3 of 13 monthsNeeds 4 or more, not met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Test projects without physical hardware
“This is a great idea. It’s always been inconvenient requiring access to the physical board just to be able to test these sort of projects.”
Comment from 27 Mar 2026 in “Velxio 2.0 – Emulate Arduino, ESP32, and Raspberry Pi 3 in the Browser” “Being able to iterate without constantly flashing hardware can save a lot of time early on.”
Comment from 28 Mar 2026 in “Velxio 2.0 – Emulate Arduino, ESP32, and Raspberry Pi 3 in the Browser” “this would save a lot of soldering time”
Comment from 28 Mar 2026 in “Velxio 2.0 – Emulate Arduino, ESP32, and Raspberry Pi 3 in the Browser” No setup or toolchains required
“no setup is required on the user's side, no toolchains need to be installed”
Comment from 27 Mar 2026 in “Velxio 2.0 – Emulate Arduino, ESP32, and Raspberry Pi 3 in the Browser” “It runs immediately, no setup required”
Comment from 28 Mar 2026 in “Velxio 2.0 – Emulate Arduino, ESP32, and Raspberry Pi 3 in the Browser” Runs locally with no cloud
“trying to push further into full multi-board emulation and local-first workflows”
Comment from 28 Mar 2026 in “Velxio 2.0 – Emulate Arduino, ESP32, and Raspberry Pi 3 in the Browser” “No cloud dependency. No student accounts. No data leaving your network.”
Comment from 27 Mar 2026 in “Velxio 2.0 – Emulate Arduino, ESP32, and Raspberry Pi 3 in the Browser” Multiple boards with full peripherals
“Velxio supports multiple heterogeneous boards in the same circuit”
Comment from 28 Mar 2026 in “Velxio 2.0 – Emulate Arduino, ESP32, and Raspberry Pi 3 in the Browser” “peripherals are fully emulated, not just the CPU”
Comment from 28 Mar 2026 in “Velxio 2.0 – Emulate Arduino, ESP32, and Raspberry Pi 3 in the Browser”
Other firmware emulators people recommend
The four most recommended other firmware emulators, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| VelxioThis page | 21 | 3 | 88% | 3 | — | — |
| Diode | 17 | 10 | 63% | 1 | — | — |
| Circuit Artist | 11 | 0 | 100% | 2 | — | — |
| Esp32sim | 11 | 1 | 92% | 1 | — | — |
| LTspice | 10 | 2 | 83% | 6 | — | Approved |
What people said
27 of the 33 comments that mention it, newest first. Each links to the original comment.
“we run the compiled firmware image directly inside a browser-based hardware simulator CLI (velxio-cli)”
“One of the best circuit emulators out there!”
“I cannot give it an ESP32-C6 firmware binary to execute, I have to compile my source code (C only)”
“peripherals are fully emulated, not just the CPU”
“Really impressive - browser-based hardware emulation is a brutal WebAssembly performance problem.”
“That looks awesome, thank you for your hard work!”
“it takes away the learning in my eyes”
“I tried the example but didn't see e.g. LEDs blinking”
“It runs immediately, no setup required”
“trying to push further into full multi-board emulation and local-first workflows”
“Being able to iterate without constantly flashing hardware can save a lot of time early on.”
“I like this Idea but I don't want to use this.”
“this would save a lot of soldering time”
“it runs well on my old android phone”
“The visual component editor does look pretty nice”
“Velxio supports multiple heterogeneous boards in the same circuit”
“I look forward to trying this out though, great project!”
“Scrolling the canvas is sometimes problematic. Otherwise very interesting.”
“it wasn’t immediately clear that you need to press Compile before Play gets enabled”
“This is a great idea. It’s always been inconvenient requiring access to the physical board just to be able to test these sort of projects.”
“no setup is required on the user's side, no toolchains need to be installed”
“Awesome work! Playing with it now.”
“No cloud dependency. No student accounts. No data leaving your network.”
“If anyone wants a quick thing to try in the simulator”
“All I see are dependencies that are glued together with claude.”
“Still very cool, would try it later.”
“Very cool. I can't wait to play around with this!”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.