ngspice
Shares rank 10 of 12 firmware emulators by recommenders
Free circuit simulator that people use for real engineering work. Critics call its core code dated, say it assumes outdated systems, and find switching to xschem clumsy.
Free circuit simulator that people use for real engineering work. Critics call its core code dated, say it assumes outdated systems, and find switching to xschem clumsy.
10 people gave an opinion
- recommend it
- 5
- criticize it
- 5
- approval share
- 50%
Recommended in 3 of 13 months
- November 2025: not recommended
- December 2025: not recommended
- January 2026: not recommended
- February 2026: recommended
- March 2026: not recommended
- April 2026: not recommended
- May 2026: recommended
- June 2026: not recommended
- July 2026: not recommended
- August 2026: not recommended
- September 2026: recommended
- October 2026: not recommended
- November 2026: not recommended (month in progress)
Why it doesn’t carry the badge
- 5 people recommend itNeeds 10 or more, not met.
- 1 recommender for every criticNeeds 2 to 1 or better, not 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
Used for real engineering work
“they were written to get a real job worth real money done”
Comment from 10 May 2026 in “Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc” “It was even able to do complex ngspice simulations.”
Comment from 5 Sep 2026 in “Can AI design circuit boards yet?” Functional, performance-tuned code base
“That sounds like a perfectly functional project, to me.”
Comment from 9 May 2026 in “Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc” “That code is also hyper-optimized for performance”
Comment from 10 May 2026 in “Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc”
What people warn about
Each mark is one comment
Dated, Fortran-era core code
“the interface in the original spice core is a mess of string handling and building a custom shell experience”
Comment from 11 May 2026 in “Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc” “Ngspice shows its heritage from the days of Fortran far more than a modern code base would or should.”
Comment from 10 May 2026 in “Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc” “The spice core that ngspice is built off is terrible code.”
Comment from 9 May 2026 in “Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc” Assumes outdated systems and hardware
“I download on Mac, run `ngspice`, "Error: Can't open display: :0". I look in the code - hardcoded X11-era assumptions.”
Comment from 9 May 2026 in “Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc” “this project is way behind time and is going to pose a lot of issues to new users”
Comment from 9 May 2026 in “Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc” “very far from optimized for modern CPUs”
Comment from 10 May 2026 in “Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc”
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 | — | — |
| ngspiceThis page | 5 | 5 | 50% | 3 | — | — |
What people said
12 of the 13 comments that mention it, newest first. Each links to the original comment.
“Ngspice is okay but it's a bit clumsy switching between it and xschem.”
“It was even able to do complex ngspice simulations.”
“the interface in the original spice core is a mess of string handling and building a custom shell experience”
“very far from optimized for modern CPUs”
“Ngspice shows its heritage from the days of Fortran far more than a modern code base would or should.”
“That code is also hyper-optimized for performance”
“they were written to get a real job worth real money done”
“this project is way behind time and is going to pose a lot of issues to new users”
“The spice core that ngspice is built off is terrible code.”
“I download on Mac, run `ngspice`, "Error: Can't open display: :0". I look in the code - hardcoded X11-era assumptions.”
“a project presenting at FOSDEM certainly does not need a "revive"”
“That sounds like a perfectly functional project, to me.”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.