Free Electronics and PCB Software — Alternatives to Altium, OrCAD and the Simulators
In electronics the gap between free and commercial tools has almost closed. An engineer designing a mid-complexity board, simulating an analogue circuit or verifying an RTL block can do all of it without a single licence — and it is not a compromise. Here is what exists, sorted by the kind of work.
Printed circuit board design
1. KiCad
The real alternative to Altium and OrCAD. Hierarchical schematics, component libraries, layout with a push-and-shove router, DRC, a 3D viewer and full Gerber output. There is no limit on layer count, board area or component count — which is exactly where the "free" editions of commercial packages fall down.
What is missing: a full built-in autorouter, and advanced signal- and power-integrity analysis. For very high-speed boards people still turn to commercial tools.
2. LibrePCB
Younger, with an unusually disciplined approach to library management — each part is defined once and linked, instead of being duplicated across projects. The interface is clean and quick to start with.
What is missing: a smaller ecosystem than KiCad's, and fewer ready-made manufacturer libraries.
3. gEDA
A veteran suite: schematic capture, netlisting, symbol libraries and PCB layout. Traditional in character, but stable and completely open.
KiCad
KiCad Development Team
Open-source PCB design suite, from schematic to fabrication files, with no limit on layers or board area.
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LibrePCB
LibrePCB
Modern PCB design with a unified component library — schematic, layout and fabrication files.
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gEDA
gEDA Project
A suite of tools for schematic capture, netlisting and PCB design.
Get it from the vendorAnalogue simulation
4. LTspice
A free SPICE simulator from Analog Devices, very fast and with no node limit, carrying a power-component library and manufacturer models. The de facto standard for switching converter design.
What is missing: it is closed source. There is no access to the engine, and the libraries lean towards the vendor's own parts.
5. Ngspice
The open-source SPICE engine. You run it from the command line or from inside other tools, and it is what makes real automation possible — parameter sweeps, Monte Carlo runs and scripted analysis.
6. Qucs-S
A graphical schematic editor running established SPICE engines behind it. It gives DC, AC, transient, noise and S-parameter results — convenient for analogue and RF work.
7. Falstad Circuit Simulator
Runs in the browser and draws current as moving dots. Not a design tool — but the fastest way to explain or grasp what a circuit actually does, which makes it worth its weight in teaching.
LTspice
Analog Devices
Fast SPICE simulator with no component limit, unusually strong on switching converters and power circuits.
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Ngspice
Ngspice Project
Open-source SPICE simulator — DC, AC, transient and noise. The engine behind KiCad simulation.
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Qucs-S
Qucs-S Project
Circuit simulation with a graphical schematic front end over SPICE engines.
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Falstad Circuit Simulator
Paul Falstad
An interactive circuit simulator that runs in the browser, with animated current.
Get it from the vendorDigital design and verification
8. Verilator
Converts synthesisable Verilog and SystemVerilog into a C++ model that runs orders of magnitude faster than event-driven simulators. Used in real chip projects for regression testing and co-simulation with software.
9. Icarus Verilog
A small Verilog compiler and simulator, quick to install, which dumps waveforms. Enough for coursework and for verifying modest blocks.
10. GTKWave
Displays the waveforms that whole flow produces — VCD, LXT, FST. The permanent companion to any open-source simulation.
11. Logisim-evolution
Interactive construction and simulation of logic circuits, with FPGA export. The standard teaching tool for digital design.
12. Electric VLSI
Custom IC layout, schematic capture and LVS/DRC checking in one package, with links to external simulators. A practical free option for teaching VLSI.
Verilator
Veripool
Compiles synthesisable Verilog into fast C++ — the quickest free RTL simulator.
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Icarus Verilog
Stephen Williams
A Verilog compiler and simulator for digital design work.
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GTKWave
GTKWave Project
A waveform viewer for digital simulation output.
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Logisim-evolution
Logisim-evolution Team
Design and simulate digital logic circuits interactively.
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Electric VLSI
Static Free Software
An IC and schematic design system covering layout, schematics and simulation links.
Get it from the vendorElectrical panels and documentation
13. QElectroTech
Wiring and control schematics with IEC symbols, automatic wire numbering, cross-references and terminal list export. Aimed squarely at panel and installation documentation — not at electronics.
QElectroTech
QElectroTech Project
Draws electrical panel and control diagrams from standard symbol libraries.
Get it from the vendorWhat to pick
If you design boards: KiCad, without hesitation. If you simulate analogue power: LTspice. If you need automation around the simulation: Ngspice. If you verify RTL: Verilator with GTKWave. That combination covers the overwhelming majority of the work, and every one of them is used in real production rather than only in a classroom.
All electronics tools on the site: the electronics and EDA category, and the electrical and electronics engineering field.