⚠️ Important update: withdiode.com (Diode) has been offline since April 2026 after going viral on Hacker News. If you’re looking for a working alternative, read on. We’ve also updated our original Diode review with this notice.
You had been using Diode to simulate circuits in the browser. It was free, it was 3D, it needed no installation. Then one day in April 2026, you tried to open it and the site simply wasn’t there.
What happened is the classic Hacker News hug of death: withdiode.com was posted to the community, hit the front page, tens of thousands of people poured in at once, and the servers couldn’t handle it. Since then, the site has stayed offline.
Searches for alternatives spiked immediately — terms like “diode simulator alternative”, “withdiode down”, and “free online circuit simulator” saw a sharp rise. And there’s one clear answer: Tinkered.ai.
What was Diode (withdiode.com)?
For those who never used it: Diode was an electronics circuit simulator that ran entirely in the browser. No downloads, no installation, free. It let you build circuits in a visual 3D environment, program Arduinos, and observe hardware behavior before ever picking up a soldering iron.
It was especially popular among students, makers, and electronics enthusiasts for its accessibility and visual approach. Our full analysis is still available here: Diode: Free Online 3D Circuit Simulator Review.
The problem: it was never backed by enterprise-grade infrastructure. When traffic multiplied overnight due to the Hacker News effect in April 2026, the servers gave out — and haven’t come back.
Tinkered.ai: Everything Diode Did, and Much More
Tinkered.ai is the natural successor to Diode. It was built as a direct alternative to withdiode.com — they even have a dedicated landing page at tinkered.ai/withdiode — and covers exactly the same use case: simulate circuits in 3D from the browser, without installing anything.
But that’s where the similarity ends.
3D Browser Simulation (Same as Diode, Improved)
Tinkered keeps the visual approach that made Diode so intuitive: a photorealistic 3D environment where components are placed and connected like a real breadboard. Every component is rendered at real-world scale with accurate materials and lighting. You see the circuit exactly as it will look on your desk before buying a single part.
The key difference is under the hood: while Diode used a basic simulation engine, Tinkered runs real SPICE analog physics. Resistors, capacitors, transistors, and op-amps behave like actual physical components — voltage drops, current flow, signal integrity. This is not a visual approximation; it’s genuine electrical simulation.
Cycle-Accurate AVR Emulation
Were you simulating Arduino with Diode? Tinkered does the same, but with cycle-accurate ATmega instruction set emulation. Every clock cycle of your firmware runs against the real instruction set: same timing, same interrupts, same edge cases. Exactly how the physical chip would execute it.
This matters when your project depends on precise timing or interrupt-driven logic. With Diode, if the sketch compiled and seemed to work, you’d take the plunge and build. With Tinkered, you know it actually works before you touch the soldering iron.
ESP32 Support and 1,300+ Boards
This was one of Diode’s biggest limitations: it only supported Arduino Uno. Tinkered supports Arduino, ESP32, Raspberry Pi Pico, and over 1,300 boards. If you work with smart home automation, IoT, or electrical control systems — as much of this blog’s audience does — ESP32 support is a massive leap forward.
You can generate firmware and compile for any board. If it exists, Tinkered builds for it.
AI That Generates Circuits From Plain Text
This is the most significant addition over Diode: AI-powered circuit generation.
Describe your project in plain English: “I want a temperature sensor with an ESP32 that turns on an LED when it exceeds 30 degrees.” Tinkered interprets the description, selects components, maps pin assignments, and writes the firmware. You iterate by chatting instead of redrawing schematics from scratch.
The output is a complete circuit ready to simulate, plus firmware code, plus a parts list with exact specifications, plus step-by-step assembly instructions. Everything is automatically generated and fully editable if you want to fine-tune anything manually.
Full Workflow: From Simulation to Real Hardware
Diode was simulation-only. Tinkered closes the complete loop:
- Describe — plain English text, AI generates components and firmware
- Wire — in the 3D editor, automatically or manually
- Simulate — real SPICE physics + cycle-accurate AVR emulation
- Deploy — one click flashes firmware to your real board
One click sends firmware to Arduino, ESP32, Raspberry Pi Pico, or any of the 1,300+ compatible boards. No terminal, no toolchain setup, no driver hunting.
Comparison: Tinkered vs Diode (withdiode.com)
| Feature | Diode (offline) | Tinkered.ai |
|---|---|---|
| 3D browser simulator | ✅ | ✅ |
| No download or install | ✅ | ✅ |
| Free | ✅ (was free) | ✅ (free beta) |
| Arduino support | ✅ | ✅ |
| ESP32 support | ❌ | ✅ |
| Real SPICE physics | ❌ | ✅ |
| Cycle-accurate AVR emulation | Basic | ✅ Full |
| AI circuit generation from text | ❌ | ✅ |
| Deploy to real hardware | ❌ | ✅ |
| 1,300+ supported boards | ❌ | ✅ |
| Waveform viewer | Not documented | ✅ |
| Component failure simulation (magic smoke) | ✅ | ✅ |
| Current status | ❌ Offline | ✅ Live |
Who Is Tinkered For?
Students and educators: No lab budget? Simulate circuits for class, share projects via link, and learn electronics without buying a single component.
Makers and hobbyists: Test your idea before ordering parts. See it work in 3D simulation before you solder a wire. And if something fails in simulation — including the magic smoke when you short the battery — it fails before it costs you money.
Engineers and professionals: Cycle-accurate AVR emulation plus SPICE analog physics deliver the simulation depth needed for serious work, with zero environment setup.
Is It Really Free?
Yes. Tinkered is free during beta. No credit card, no installation, no catch. Just like Diode was in its time, it runs entirely in the browser from day one.
How to Get Started
- Go to tinkered.ai or directly to the Diode migration page: tinkered.ai/withdiode
- Create a free account (beta is open)
- Describe your project or jump straight into the 3D editor
No migration needed. If you had projects in Diode and remember what they did, Tinkered’s AI can help you rebuild them from a text description.
Conclusion
withdiode.com was a pioneering tool that democratized browser-based circuit simulation. Its collapse in April 2026 left a real gap — particularly for students and makers who depended on it to learn and prototype without physical hardware.
Tinkered.ai is not just a replacement: it’s what Diode would have wanted to become with more time and resources. Same visual, accessible approach; much stronger technical foundation (real SPICE, cycle-accurate emulation); and the generational leap of applied AI for hardware design.
If you used Diode, you already know what you’ve lost. Tinkered gives it back — plus everything Diode never had.
Found this useful? We also have a full analysis of EveryCircuit as a circuit simulator and our guide to simulation tools for electricians.
