Ngspice is primarily a command-line simulator, not a complete schematic-capture application.
Buyers who expect to draw circuits and inspect waveforms in one GUI should budget time to select and configure a separate frontend.
Evidence source ↗
Ngspice
Ngspice is an open-source SPICE simulator for analog and mixed-signal circuits. It runs from the command line or as a shared library embedded in other applications.
6 key claims verifiedOur editorial team checked this profile against vendor documentation, product documentation. Supported by 5 documented sources.
Editorial overview
Aggregated Overview
The documented simulator includes analog and mixed-signal capabilities, multiple analysis modes, and a shared-library interface. It is free under a modified BSD license, but its command-line focus and compilation or frontend setup can require technical experience.
This profile combines documented product information and independent evidence where available. It is not a hands-on test unless TechZella explicitly identifies one.
Overview
Ngspice is an open-source simulator for analog and mixed-signal circuits. It descends from SPICE3, CIDER, and XSPICE codebases, and runs as a command-line program or shared library.
The simulator supports common circuit analyses, while separate applications provide schematic capture and graphical workflows. Examples of documented integrations include KiCad, XSCHEM, and Qucs-S.
Ngspice Decision Snapshot
A quick way to understand who this product may suit, where its limits matter, and which facts are most relevant before you compare alternatives.
Best suited to
Circuit designers and engineering developers who need a free SPICE simulation engine, scriptable netlist workflows, or an embeddable simulator for a custom application.
Look elsewhere if
Users who need an integrated schematic editor and turnkey graphical workflow may prefer a frontend such as Qucs-S or KiCad, which uses Ngspice as its simulation engine, and should evaluate alternatives such as LTspice instead.
Platforms
API, BSD, Linux, macOS, Windows
TechZella assessment
7.8/10
Ngspice — What Sets It Apart?
These are the product-specific differences that may matter when deciding whether the software fits your workflow. They are based on documented evidence rather than a universal ranking.
- Can run as a standalone command-line simulator or as a shared library controlled by another application.
- XSPICE adds event-driven simulation capabilities for circuits combining analog and digital elements.
- Its open, modified-BSD licensing and source availability support integration into engineering toolchains.
Ngspice Pros & Cons
Pros
- Free and open source under a permissive modified BSD license for most code.
- Offers both standalone command-line use and shared-library embedding.
- Supports analog, mixed-signal, and event-driven simulation workflows.
- Has documented integration with multiple EDA and schematic tools.
Cons
- The core simulator is command-line oriented and does not provide an integrated schematic editor.
- The project website does not currently offer a macOS release binary.
- Linux users may need to compile from source or accept distribution packages that lag the latest release.
Ngspice Gotchas & Operational Limits
These are documented constraints or practical friction points that may matter before you adopt the product.
The download options differ by operating system.
The official page lists Windows binaries, points macOS users to Homebrew, and says Linux users should use distribution packages or compile the source.
Evidence source ↗Ngspice Pricing & Plans
Open-source software
$0
Ngspice is distributed under a modified BSD license for most source code; the project lists no paid plans or trial.
Check current pricing →Pricing may change. Verify current plans on the vendor's website.
Ngspice Competitors & Alternatives
Compare similar products directly, then see which alternatives may make more sense when your requirements differ.
At a glance
Developer Tools| Decision factor | Ngspice | LTspice | Qucs-S |
|---|---|---|---|
| Pricing model | Free software distributed under a modified BSD license. | Analog Devices describes LTspice as free software. Source ↗ | Qucs-S is an open-source project; its public repository is available for download. Source ↗ |
| User interface | Command-line simulator with graphics output; graphical schematic workflows use separate frontends. | Includes graphical schematic capture and a waveform viewer. Source ↗ | Provides a Qt-based graphical interface for schematic capture and circuit simulation. Source ↗ |
| Simulation architecture | Standalone SPICE engine with an embeddable shared-library interface. | Standalone SPICE simulator with schematic capture and waveform viewing in its application. Source ↗ | Frontend that can use Ngspice, Xyce, SpiceOpus, and Qucsator simulation engines. Source ↗ |
| Supported desktop platforms | The project documents source builds for Linux, Windows, macOS, and BSD; current website binaries are listed for Windows. | Analog Devices lists downloads for Windows and macOS, including Windows ARM64. Source ↗ | The Qucs-S repository lists support for Linux, Windows, FreeBSD, and macOS. Source ↗ |
Only factors supported by the available research are shown. The comparison is descriptive, not a ranking.
Direct competitors
These products address broadly similar requirements. The descriptions focus on documented reasons a buyer might compare them with Ngspice.
Ngspice Features
Circuit simulation
- DC operating-point and sweep analysis
- AC small-signal analysis
- Transient analysis
- Noise, sensitivity, pole-zero, and distortion analyses for applicable analog circuits
- XSPICE event-driven mixed-signal simulation
Integration and automation
- Shared-library interface with control functions and callbacks
- Command-line netlist workflows
- Python interfaces are listed among third-party integrations
Compatibility and ecosystem
- KiCad schematic-editor integration
- Can be used with Qucs-S and XSCHEM
- Supports external device models and code models
Demo & Screenshots
Ngspice Specifications
| License | Modified BSD for most source code; Tclspice and numparam use LGPLv2, and XSPICE is public domain |
|---|---|
| Latest stable release | Ngspice 47 |
| Platforms | Source builds: Linux, Windows, macOS, BSD, Solaris; binary availability varies |
| Interface | Command line, graphical output, shared-library API |
| Deployment | Locally installed or embedded as a shared library |
| Pricing model | Free and open source |
| API | Shared-library interface documented in the user manual |
Deployment & System Footprint
Verified installation, hosting, administration, or environment details that can affect implementation.
| Installation or hosting | Locally installed software. The project distributes source code and Windows binaries; Linux users may use distribution packages or compile from source. Source ↗ |
|---|---|
| Embedding | Can be compiled as a shared library and controlled by a host application through exported functions and callbacks. Source ↗ |
Migration & Lock-In
Documented portability, standards, export, or switching considerations. No switching-cost score is shown unless the evidence supports one.
Circuit inputs and outputs
Simulation workflows use circuit descriptions and netlists; the manual describes reading netlists, preprocessing them, running simulation, and processing results.
Evidence source ↗Our evidence-based assessment
TechZella Score
A proprietary editorial score based on product capabilities, usability, value, performance, support and user sentiment evidence.
7.8/10Moderate confidence
The documented simulator includes analog and mixed-signal capabilities, multiple analysis modes, and a shared-library interface. It is free under a modified BSD license, but its command-line focus and compilation or frontend setup can require technical experience.
Methodology v1.0. The assessment weighs feature coverage (25%), ease of use (15%), value for money (20%), performance (15%), support (10%) and user sentiment (15%), using researched product evidence and verified review evidence where available. It is a TechZella editorial assessment, not a direct user-review average.
Editorial transparency
Our Review Methodology
Key claims are linked to the sources used to verify them. This evidence record is separate from third-party user ratings.
TechZella evaluates software using documented product capabilities, pricing information, usability and value considerations, independent user evidence where available, and competitive context. The assessment is an editorial review, not a hands-on test unless one is explicitly identified. Our editorial assessment is based on 5 documented sources.
What TechZella adds
- Can run as a standalone command-line simulator or as a shared library controlled by another application.
- XSPICE adds event-driven simulation capabilities for circuits combining analog and digital elements.
- Its open, modified-BSD licensing and source availability support integration into engineering toolchains.
Important limitations
- The core program is command-line oriented; graphical schematic editing is available through separate applications rather than the simulator itself.
- The current download page lists Windows binaries, but not a current macOS release; macOS users are directed to third-party package options.
- Linux users may need to use a distribution package or compile the source, and package versions can lag the current release.
Evidence-backed claimsNgspice 47 is the current stable release listed by the project. Ngspice supports shared-library integration. Ngspice source builds are documented for Linux, Windows, macOS, BSD, and Solaris. The source code is generally licensed under a modified BSD license, with noted exceptions. KiCad integrates Ngspice for schematic-based circuit simulation. Ngspice 47 added or updated several capabilities, including Python matplotlib plotting and WAV file reading and writing.
The official download page identifies ngspice-47 as the latest stable release.
View source ↗Verified 2026-11-10The project describes a shared module that exposes simulator-control functions and callbacks to a host application.
View source ↗Verified 2026-11-10The download page names these operating systems for compiling the source; binary availability differs by operating system.
View source ↗Verified 2026-11-10The manual describes modified BSD licensing for most source code, LGPLv2 for Tclspice and numparam, and public-domain licensing for XSPICE.
View source ↗Verified 2026-11-10KiCad's product page says its schematic editor integrates Ngspice and provides several standard simulation modes.
View source ↗Verified 2026-11-10The project news page lists those items among the release 47 enhancements.
View source ↗Verified 2026-11-10Ngspice FAQs
Answers begin with the clearest available response, followed by the context that helps you act on it.
Is Ngspice free?
Yes. The project distributes Ngspice as open-source software under a modified BSD license for most code, with documented exceptions.
Does Ngspice include a graphical schematic editor?
No integrated schematic editor is documented for the core simulator. Separate applications, including KiCad and Qucs-S, provide graphical workflows using Ngspice.
Can Ngspice be embedded in another application?
Yes. It can be compiled as a shared library and controlled through an exported interface with callbacks.
Which operating systems does Ngspice support?
The project documents source builds for Linux, Windows, macOS, BSD, and Solaris. Binary availability varies; the website currently lists Windows packages and directs macOS users to Homebrew.
Does Ngspice have a free trial?
No. A trial is not listed. The project offers the software under an open-source license rather than a time-limited trial plan.
Community feedback
Reviews
No reviews yet. Be the first to share your experience.
Write a Review
Please log in to submit a review.