ngspice
Open source SPICE circuit simulator for analog, digital, and mixed signal circuits, driven by netlists and the command line.
What it does and how it connects
ngspice is the open source SPICE simulator for electric and electronic circuits. It simulates circuits described as a netlist, covering JFETs, bipolar and MOS transistors, passive elements, diodes, and transmission lines, with digital circuits simulated event-driven and fast, and mixed-signal combinations supported.
It offers device models from its own collections, semiconductor manufacturers, and foundries, and is SPICE compatible: it can apply PSpice or LTspice device model parameters and netlists, and read HSPICE libraries from foundry PDKs. It provides no schematic entry of its own; input is command line or file based, with third-party interfaces available.
The project is developed in the open, with source and Windows binaries on SourceForge and packages in Linux distributions, Cygwin, FreeBSD, and Homebrew for macOS. The license is BSD-3-Clause, per the project's developer page.
The GitHub repository is a low-activity mirror; ngspice development happens on SourceForge, so the last push date here understates activity. No GitHub releases exist, so latest release fields are null.
What engineers report
I would like to request clarification and/or feature support for true device-noise injection during transient analysis, especially for MOS/BSIM devices.
2026-07-09Read the original
Alternatives
Compare side by side- LTspice
LTspice is a free SPICE simulator from Analog Devices with schematic capture and a waveform viewer for simulating analog circuits.
- KiCad
KiCad is a free, open-source electronics design suite with a schematic editor, PCB layout editor, integrated SPICE simulation, and a 3D viewer.
- Proteus
Proteus is a design suite from Labcenter that combines schematic capture and PCB layout with circuit and microcontroller simulation.
- Cadence OrCAD/Allegro
OrCAD X includes built-in PSpice analog and mixed-signal circuit simulation inside the schematic and layout environment.
Sources
Not verified
- Pricing: none stated on the vendor site or repo as read.
- Related Error Index entries: no entry with software ngspice was verified.
Last verified November 6, 2026. Listings are informational. The evidence score measures public, verifiable evidence and is not an endorsement or a compatibility claim.