Proteus is the tool many people first meet in an embedded systems lab, and KiCad is the one they install at home. Both take a circuit from schematic to Gerbers. Only one of them can run your compiled firmware on a simulated microcontroller, and that single feature settles most of these comparisons.
By Rishik Boddeti · Last reviewed
Founder of ProtoFlow, ECE at UT Austin
Quick answer
Choose Proteus if you need to run real firmware against a simulated circuit: Proteus VSM loads a compiled HEX or ELF file onto the microcontroller in your schematic and stops the whole circuit at your breakpoints. Choose KiCad if you need schematic capture and PCB layout with no license cost, native Windows, macOS and Linux builds, and SPICE simulation through ngspice. Proteus is a paid, Windows-only suite sold per module, from $248 for the PCB Design Starter Kit and $322 for VSM for Arduino AVR. For board design without firmware simulation, KiCad does the job for free.
| KiCad 10 | Proteus 9 | ProtoFlow | |
|---|---|---|---|
| License and cost | Free, open source (GPL) | Paid perpetual licenses, sold per module | Free plan; paid plans raise AI limits |
| Platforms | Windows, macOS, Linux | Windows on x64; ARM not supported | Windows, macOS, Linux |
| Circuit simulation | SPICE via ngspice | Basic SPICE included; Advanced Simulation is a $372 add-on | SPICE via ngspice: OP, transient, AC, DC sweep |
| Microcontroller and firmware simulation | None | VSM, sold per MCU family | Analog SPICE (ngspice) |
| Board size limits | None by license; up to 32 copper layers | Tiered by level (Level 2: 1,000 netlist pins) | Full editor on the free plan |
| 3D and MCAD output | STEP, GLB, STL, VRML, IDF and more | STEP and IGES from PCB Level 2 up | 3D view; DXF import from mechanical CAD |
| Built-in AI | None built in | ProPilot assistant (schematic analysis, firmware code help) | Prompt-to-schematic drafting, AI Copilot, AI Part Generator |
| Free version | The whole program | Demo: no saving, 14-day MCU simulation | Free plan, no card, no expiry |
Skip the comparison shopping. Try the free one first and see if it does the job.
Download for DesktopEach row links to the vendor page it came from and shows the date we last read that page. Vendors change pricing often, so check the link before you buy.
| Product | Price or limit | Source | Checked |
|---|---|---|---|
| KiCad | Free and open source; no paid edition | kicad.org | |
| Proteus PCB Design | Starter Kit $248; Level 1 $537; Level 2 $1,032; Level 3 $2,104 (single commercial user, USD) | labcenter.com | |
| Proteus PCB Design Level 2 | 1,000 pins in netlist | labcenter.com | |
| Proteus VSM | Arduino AVR $322; ARM Cortex-M3 or M4 $908 | labcenter.com | |
| Proteus Advanced Simulation | $372 add-on | labcenter.com | |
| Proteus Platinum Edition | $8,622 | labcenter.com | |
| Proteus demo | Free; cannot save work; 14-day microcontroller simulation | labcenter.com |
Labcenter describes VSM as microcontroller and mixed-mode SPICE simulation inside the schematic. You attach a program file (HEX, COF, ELF/DWARF2, UBROF and others) as a property of the microcontroller part, run the simulation, and watch the firmware drive the rest of the circuit. Set a breakpoint and the entire system stops on that line; single-step and the circuit advances with it. Rewire the schematic or change a resistor, recompile, and run again.
The instruments come with it. Labcenter lists a DSO, a logic analyser and I2C and SPI protocol analysers among VSM's tools, and its VSM Studio IDE is included as standard. Support is sold per processor family, with modules for PIC, AVR, 8051, MSP430, ARM Cortex-M0, M3 and M4, Arduino AVR and MicroPython, among others.
KiCad's simulator is ngspice. It analyses the circuit at the SPICE level and plots the results, and it does not execute firmware. If the point of the exercise is debugging code against hardware before the hardware exists, no KiCad setup replaces VSM.
KiCad is free and open source under the GPL, with no editions, no pin caps and no demo mode. The same program handles a two-layer student board and a 32-copper-layer production design, and it runs natively on Windows, macOS and Linux. Schematic capture includes ERC and ngspice simulation; layout includes differential-pair routing, length tuning, DRC, and outputs from Gerber and drill files to ODB++, IPC-2581 and STEP.
KiCad's import list is broad (Altium, EAGLE, EasyEDA, PADS, CADSTAR, gEDA, and LTspice schematics among others) but it does not include Proteus. Moving an existing Proteus design into KiCad means redrawing the schematic and placing the board again, so budget for that if you plan to switch partway through a project.
Proteus is sold as perpetual licenses, module by module. Labcenter's commercial price list (single user, shown in US dollars from the US) puts the PCB Design Starter Kit at $248, Level 1 at $537, Level 2 at $1,032 and Level 3 at $2,104. Level 2 is listed with 1,000 pins in the netlist, so board size is part of what you buy. The Advanced Simulation option is $372, individual VSM families run from $322 (Arduino AVR) to $908 (ARM Cortex-M3 or M4), and the Platinum Edition with everything is $8,622.
New releases come through an Update Service Contract. Labcenter's FAQ says customers without a current contract can keep using the version they have indefinitely, but must reactivate the contract to install later releases.
The free demo is a genuine evaluation with limits that matter: you cannot save your work, microcontroller simulation runs for 14 days, and it only runs the bundled sample designs, not your own microcontroller projects.
Labcenter's published requirements are for Microsoft Windows on an x64 Intel or AMD processor, and its FAQ states that ARM processors such as Snapdragon are not supported. That rules out Windows-on-ARM laptops and, in practice, Windows virtual machines on Apple Silicon Macs, which run the ARM build of Windows. KiCad has native macOS and Linux builds, so the question does not come up.
Some Proteus outputs depend on the level you buy. Every Proteus PCB Design Professional level writes Gerber (including X2) and Excellon drill files; ODB++ output and the 3D viewer with STEP export start at Level 2. Proteus 9.2 added HDI micro-via support and an Output Job Manager, and its ProPilot assistant reads the schematic to help with part choices, firmware code and debugging, using a language model you choose.
Where ProtoFlow helps is the board itself. It is a free desktop app for Windows, macOS and Linux that drafts an editable schematic with real parts from a plain-language prompt, runs ngspice operating-point, transient, AC and DC sweep analyses with a waveform viewer, lays out and autoroutes the PCB, and writes Gerber X2, drill, BOM and CPL files for JLCPCB assembly. It exports KiCad projects, so you can continue in KiCad whenever you like.
A split that works for many embedded projects: debug the firmware against a simulated MCU in Proteus, then build the production board in KiCad or ProtoFlow, redrawing the schematic once.
| Criteria | ProtoFlow | KiCad or Proteus |
|---|---|---|
| Run firmware on a simulated MCU | No. | Proteus VSM yes; KiCad no. |
| Analog SPICE checks | ngspice: OP, transient, AC and DC sweep. | KiCad uses ngspice; Proteus includes basic SPICE, more with Advanced Simulation. |
| Cost to start | Free plan, no card. | KiCad free; Proteus from $248 per module. |
| macOS and Linux | Native on both. | KiCad native; Proteus Windows only. |
| Opening Proteus projects | Not supported. | Proteus only; KiCad has no Proteus importer. |
| AI help | Prompt-to-schematic drafting and an in-editor Copilot. | Proteus has ProPilot; KiCad has none built in. |
Reviewed on: 2026-10-14
No. KiCad's simulator is ngspice, which analyses circuits at the SPICE level but does not execute firmware. Proteus VSM runs a compiled program on the simulated MCU and steps the whole circuit with it.
No. Proteus is sold as paid perpetual licenses per module, starting at $248 for the PCB Design Starter Kit and $322 for VSM for Arduino AVR (single commercial user). The free demo cannot save your work and limits microcontroller simulation to 14 days.
Labcenter publishes requirements only for Windows on x64 processors, and says ARM processors are not supported. KiCad has native builds for Windows, macOS and Linux.
Not directly. KiCad's documented import formats include Altium, EAGLE, EasyEDA, PADS, CADSTAR, gEDA and LTspice schematics, but not Proteus. Plan to redraw the schematic and place the board again.
Learn the one your course uses for coursework, since many embedded courses teach with Proteus VSM and Labcenter sells education licenses. For your own boards outside the lab, KiCad is free on any laptop and has no pin limits.
For the board, yes. ProtoFlow covers AI-drafted schematics, ngspice analysis, PCB layout and JLCPCB-ready outputs on its free plan, and many teams pair it with Proteus when they want to simulate firmware.
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Evaluate the workflow directly with your own circuit scope and compare review-ready output speed.
