CircuitJS
Ranked 7 of 12 firmware emulators by recommenders
Free, browser-based circuit simulator that people use to prototype analog circuits and teach electronics. Critics raised no recurring complaints.
Free, browser-based circuit simulator that people use to prototype analog circuits and teach electronics. Critics raised no recurring complaints.
7 people gave an opinion
- recommend it
- 7
- criticize it
- 0
- approval share
- 100%
Recommended in 5 of 13 months
- November 2025: recommended
- December 2025: not recommended
- January 2026: recommended
- February 2026: recommended
- March 2026: not recommended
- April 2026: not recommended
- May 2026: not recommended
- June 2026: not recommended
- July 2026: not recommended
- August 2026: recommended
- September 2026: not recommended
- October 2026: recommended
- November 2026: not recommended (month in progress)
Why it doesn’t carry the badge
- 7 people recommend itNeeds 10 or more, not met.
- Nobody criticizes itNeeds 2 to 1 or better, met.
- Recommended in 5 of 13 monthsNeeds 4 or more, 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
Good for prototyping circuits
“a very useful circuit simulator which I regularly use for prototyping”
Comment from 16 Aug 2026 in “Falstad Math and Physics Simulations” “quick for prototyping custom analog circuits”
Comment from 24 Feb 2026 in “Diode – Build, program, and simulate hardware” Praised as excellent and amazing
“Also the amazing https://www.falstad.com/circuit/circuitjs.html”
Comment from 24 Feb 2026 in “Diode – Build, program, and simulate hardware” “is excellent and far better than the mess of a breadboard IMHO”
Comment from 25 Feb 2026 in “Diode – Build, program, and simulate hardware”
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 |
|---|---|---|---|---|---|---|
| Velxio | 21 | 3 | 88% | 3 | — | — |
| Diode | 17 | 10 | 63% | 1 | — | — |
| Circuit Artist | 11 | 0 | 100% | 2 | — | — |
| Esp32sim | 11 | 1 | 92% | 1 | — | — |
| CircuitJSThis page | 7 | 0 | 100% | 5 | — | — |
What people said
8 of the 10 comments that mention it, newest first. Each links to the original comment.
“CircuitJs, but you have to draw your own grid first.”
“I usually point anyone who wants to learn electronics to it.”
“a very useful circuit simulator which I regularly use for prototyping”
“It was only then that really important things started to really become second nature.”
“is excellent and far better than the mess of a breadboard IMHO”
“quick for prototyping custom analog circuits”
“Also the amazing https://www.falstad.com/circuit/circuitjs.html”
“you can try these out online with a circuit simulator”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.