Qucs-S

Circuit simulator GUI using ngspice, Xyce and other engines

★ Stars1.4k1,409 on GitHub

Last commit2 days ago17 Oct 2026

LicenceGPL-2.0SPDX, from the repository

View on GitHub ↗

From GitHub, fetched 19 Oct 2026.

Visit ra3xdh.github.io ↗

Qucs-S is a free circuit simulation program with a schematic editor that drives SPICE-compatible engines such as ngspice and Xyce, for DC, AC, transient and RF analysis.

Free alternative to

OrCAD

In collections

CAD tools for Mac

Details

Status	Open source
Licence	GPL-2.0
Platforms	Windows, macOS, Linux
Category	PCB & electronics
Website	ra3xdh.github.io
Source	GitHub

Is this your tool?

Make Qucs-S a Top Pick at the top of its category and alternatives pages.

Get featured

Related tools

KiCad

PCB & electronics

Open-source electronics design automation suite

Stars: ★ 3k
Licence: GPL-3.0
Updated: yesterday

Alternative to Altium Designer, Eagle

ngspice

PCB & electronics

Open-source mixed-signal SPICE circuit simulator

Licence: BSD-3-Clause
Updated: 3 days ago

Alternative to OrCAD

LibrePCB

PCB & electronics

Beginner-friendly open-source EDA suite

Stars: ★ 3k
Licence: GPL-3.0
Updated: 7 days ago

Alternative to Altium Designer, Eagle

Horizon EDA

PCB & electronics

Modern EDA package for schematics and PCB layout

Stars: ★ 1.3k
Licence: GPL-3.0
Updated: 15 days ago

Alternative to Altium Designer, Eagle

EasyEDA

PCB & electronics

Free browser-based schematic and PCB design

Licence: Freeware
Status: Free (proprietary)

Alternative to Altium Designer, Eagle