Comparison

Schema vs Altium Designer

The long-standing commercial standard for professional PCB design, with the deepest feature set in high-speed and rigid-flex work. Here is how the two differ, what Altium Designer does better, and which one to pick.

Last updated 26 September 2026

The short version

Choose Altium Designer if…

You do high-speed, rigid-flex or multi-board work professionally, or your organisation already runs its release process around Altium.

Visit the Altium Designer site ↗

Choose Schema if…

You want AI assistance on a cross-platform tool, and your boards do not need Altium-grade high-speed constraint management.

At a glance

Schema compared with Altium Designer
Dimension	SchemaOurs	Altium Designer
Licence / distribution	Proprietary desktop app. Free plan including a monthly allowance of agent credits; further credits sold in packs.	Proprietary commercial licence, sold per seat.
Where it runs	Desktop — macOS on Apple Silicon, and Windows and Linux on x86-64 and arm64.	Desktop — Windows.
Agent command surface	74 documented commands across the schematic and PCB editors, identical for you and for the agent.	A scripting and extension API (DelphiScript, VBScript, JScript) plus a developer SDK.
AI assistance	A natural-language agent that drives the editor through those same commands, then checks its own work with DRC and ERC.	No natural-language design agent comparable to a prompt-to-schematic flow.
Reads KiCad libraries	Yes — reads KiCad symbol and footprint libraries, and Altium schematic libraries.	Not natively. Altium uses its own library formats; KiCad libraries require conversion or an importer.
Fabrication output	Gerber RS-274X and Excellon drill, including plated and non-plated splits.	Gerber, Excellon, ODB++ and IPC-2581.

What Schema does differently

Runs on macOS and Linux as well as Windows.
A free plan, rather than a per-seat commercial licence.
A natural-language agent drives the editor through documented commands you can also issue yourself.
Reads KiCad and Altium libraries side by side.

What Altium Designer does better

Every tool on this site has things it wins on. Here are theirs.

Far deeper high-speed design tooling — length tuning, impedance control and detailed constraint management.
Rigid-flex and multi-board projects, which Schema does not attempt.
A mature supply-chain and lifecycle stack, and long-established enterprise support.
Decades of professional adoption, so hiring and process are already built around it.

The agent surface, specifically

This is the difference that is hardest to see from a feature list, so it is worth stating plainly.

Schema exposes 74 documented commands covering schematic capture and board layout — placing symbols, drawing wires, routing traces, filling zones, running checks, rendering the board, undoing. You issue them; the AI agent issues exactly the same ones.

That matters because it is what lets the agent work in a loop rather than in one shot: it can look at the design, make a change, run DRC or ERC, look at the result, and undo if it got it wrong. Every command reports what it actually did, and a command that cannot do what was asked refuses and changes nothing rather than doing something approximate.

You can read the whole vocabulary before installing anything — it is published in full in the command reference.

The commands behind the claim

Schema publishes its entire agent surface. Here are some of the 74 commands — the same ones you issue and the agent issues — so you can judge the claim rather than take it.

place_symbolPlace a new symbol.connectPut a pin on a net, landing at the nearest point of it.draw_wireDraw a wire between two pins.place_powerPlace a power/ground symbol driving a named net.validateReport document invariants that no longer hold.netsList every net, its members, and whether its name is unique.search_footprintsFind footprints in the installed libraries by description.route_traceRoute a trace between two pads.begin_routeStart an interactive route at a pad.list_unroutedList the ratsnest — the connections that still need routing.render_boardRender a synthesised image of the board for visual inspection.undoStep the sheet back through its edit history.

All 74 commands · Documentation · Guides

How this comparison was built

We make one of the tools on this page, so here is exactly what we did and did not check.

Schema is our product. We build one of the tools on this page, and we say so at the top rather than in a footnote.
Every claim about another tool is limited to durable, checkable properties — licence model, supported platforms, published file formats, documented automation interfaces.
No page here states what another tool costs. Prices change without notice, and a stale price is the most common way a comparison page becomes wrong.
Where we have not confirmed something, the table says "Not verified" instead of guessing. Vendor claims are labelled as vendor claims.
Every comparison names what the other tool does better, including cases where we would tell you to pick it.
Found a mistake? Tell us at corrections@getschema.dev and we will correct the page and update the date on it.

Last reviewed 26 September 2026. Corrections: corrections@getschema.dev

Questions people ask

Is Schema a good Altium Designer alternative?

You want AI assistance on a cross-platform tool, and your boards do not need Altium-grade high-speed constraint management. If instead you do high-speed, rigid-flex or multi-board work professionally, or your organisation already runs its release process around Altium. then Altium Designer is the better choice, and we would tell you so.

What can Schema do that Altium Designer does not?

Runs on macOS and Linux as well as Windows. A free plan, rather than a per-seat commercial licence. A natural-language agent drives the editor through documented commands you can also issue yourself. Reads KiCad and Altium libraries side by side.

What does Altium Designer do better than Schema?

Far deeper high-speed design tooling — length tuning, impedance control and detailed constraint management. Rigid-flex and multi-board projects, which Schema does not attempt. A mature supply-chain and lifecycle stack, and long-established enterprise support. Decades of professional adoption, so hiring and process are already built around it.

Can I move my existing designs into Schema?

Schema reads KiCad symbol and footprint libraries and Altium schematic libraries directly, and can convert a KiCad schematic into a Schema project. Boards are exported as Gerber RS-274X and Excellon drill files, so the output goes to any fabricator.

Other comparisons

The same treatment, for the other tools you might be weighing up.

ComparisonSchema vs KiCadThe open-source EDA suite that most of the industry treats as the baseline. Mature, free forever, and the format everything else interoperates with.ComparisonSchema vs FluxA browser-based PCB design tool built around real-time collaboration and an in-app AI assistant.ComparisonSchema vs EasyEDAA free browser-based design tool tightly coupled to the LCSC parts catalogue and JLCPCB fabrication.ComparisonSchema vs ProtoFlowAn AI-first EDA tool that generates editable schematics from natural-language prompts and exports a KiCad project.ComparisonSchema vs TraceA hosted PCB design platform with a developer-facing surface — a CLI, an API and hosted component libraries.

Roundups

Try Schema alongside Altium Designer

Free to start on macOS, Windows and Linux. It reads your existing KiCad and Altium libraries, so trying it does not mean rebuilding your parts.