This comparison usually gets framed as free versus professional, which is both condescending to KiCad and unhelpful to anyone evaluating Altium. The useful question is narrower: which specific problems does a commercial subscription solve that an open-source tool does not, and do you have those problems?
Last reviewed: 2026-08-09 · By ProtoFlow Engineering Team
Quick answer
KiCad is free, open source, and runs natively on macOS, Windows, and Linux. Altium Designer is a commercial subscription and runs on Windows only, with no macOS or Linux version. For an individual, a startup, or open hardware, KiCad handles the overwhelming majority of real boards and the money is better spent elsewhere. Altium earns its cost on team data management, mature constraint-driven design for high-speed work, supply-chain integration, and enterprise library governance. Neither ships generative AI for schematic capture, which is where a free AI-native tool like ProtoFlow fits: it is a full PCB editor that reads and writes native KiCad files, so you can use it on its own or in front of either flow.
| KiCad 10 | Altium Designer | ProtoFlow | |
|---|---|---|---|
| Licensing | Free, open source | Commercial subscription | Free |
| Platforms | macOS, Windows, Linux | Windows only | macOS, Windows, Linux |
| Constraint-driven design | Good, improving each release | Deep, mature | Standard DRC/ERC |
| Team data management | Git and your own process | Integrated (Altium 365) | Local files, Git with visual diffs, real-time collaboration (paid plans) |
| Supply-chain data | Via plugins and manual work | Integrated (Octopart) | LCSC, DigiKey, Mouser import |
| Generative AI capture | None | None | Yes, built in |
Skip the comparison shopping. Try the free one first and see if it does the job.
Download for DesktopAltium Designer is a Windows application. Altium's own system requirements list Windows 10 and 11, 64-bit, and there is no macOS or Linux build. If you work on a Mac, using Altium means running Windows in a virtual machine or on separate hardware, with the licensing, performance, and workflow friction that implies.
KiCad runs natively on all three platforms, as does ProtoFlow. For a Mac-based team this is not a preference, it is a structural difference that shows up every single day.
Three things, mostly. First, constraint-driven design that scales: rule sets, differential pairs, length matching, and impedance handling that stay manageable on a large high-speed board. Second, team data management, where Altium 365 handles library governance, version control, release management, and review in a way that does not require you to invent a process. Third, integrated supply-chain data, with component availability and pricing surfaced inside the design tool rather than in a browser tab.
If you are a team of eight shipping regulated products with a shared component library and a release process, those are not luxuries. If you are one person designing a sensor board, you will pay for all three and use approximately none of them.
Recent KiCad releases handle hierarchical design, differential pairs, length tuning, and DRC well enough that "you cannot do serious work in KiCad" stopped being true some years ago. Real commercial hardware ships on it. The open file format is a genuine advantage for version control, and the absence of licensing means adding a contributor costs nothing.
The honest remaining gaps are the enterprise ones: library governance across a team, integrated release management, and the depth of constraint handling on genuinely difficult high-speed boards. Those are real, and they are exactly the things a solo designer does not have.
Neither KiCad nor Altium drafts a schematic for you from a description. Both have assistive features; neither is generative at the capture stage. That means the most time-consuming, least intellectually interesting part of the job, placing symbols, drawing nets, finding a part that exists and is in stock, assigning footprints, is manual in both.
ProtoFlow addresses that specific stretch with AI, inside a complete PCB editor. It is free, native on all three platforms, generates the schematic from plain English with real distributor parts attached, runs ERC and DRC, lays out and auto-routes the board, and reads and writes native KiCad files. You can use it end to end, put it in front of a KiCad flow, or use it for early capture and hand off to whatever your team standardizes on.
| Criteria | ProtoFlow | KiCad or Altium |
|---|---|---|
| Cost of entry | Free. | Free (KiCad) or subscription (Altium). |
| Runs natively on macOS | Yes. | KiCad yes; Altium no. |
| AI schematic drafting | Built in. | Neither offers it. |
| Enterprise library governance | Not the focus. | Altium's core strength. |
| File compatibility | Native KiCad read/write. | KiCad native; Altium its own format. |
Reviewed on: 2026-08-09
For most boards and most designers, yes. Altium retains real advantages in team data management, enterprise library governance, integrated supply-chain data, and deep constraint handling on difficult high-speed designs. For an individual or a small team, KiCad covers the work and costs nothing.
No. Altium's published system requirements list Windows 10 and 11 (64-bit) only, with no macOS or Linux version, so Mac users run it inside a virtual machine or on separate Windows hardware. KiCad and ProtoFlow both run natively on macOS, Windows, and Linux.
KiCad can import Altium designs, and the fidelity of any cross-tool import depends heavily on the complexity of the source project. Verify footprints, layer mapping, and net connectivity after import, and re-run DRC before you trust the result.
Neither offers generative schematic capture. ProtoFlow is a free desktop editor that does, on native KiCad files, so it can sit in front of a KiCad or Altium flow, or carry the board through layout itself.
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