Altium Viewer: Open and Inspect PCB Files

Last updated: May 2026 · A tool guide for engineers, buyers, and anyone who needs to review a design they can’t open

The Altium Viewer — formally the Altium 365 Viewer — is a free, browser-based tool that lets you open and inspect PCB design files without an Altium Designer license. You upload a file, and it renders the schematic, the 2D and 3D PCB, the layer stack, and the bill of materials, with cross-probing and measurement. It is read-only: you can view, navigate, measure, and share, but not edit. Crucially, it opens more than just Altium files — it also reads EAGLE, Gerber, ODB++, and (in beta) KiCad — which makes it a handy universal viewer when someone sends you a design and you don’t have the matching CAD tool installed.

What Is the Altium 365 Viewer?

Altium 365 is Altium’s cloud platform, and the 365 Viewer is its free file-viewing front end, introduced in early 2020. It runs entirely in a modern web browser — there is nothing to install for the web version — and it is designed so people without the design software can still open, understand, review, and comment on a board. That makes it useful for buyers, managers, mechanical engineers, test engineers, and contract manufacturers who receive design files but don’t own a seat of the CAD tool.

Because it lives in the browser, sharing is built in: you can send a link so a colleague or supplier opens exactly the design you’re looking at, without emailing files back and forth.

What File Formats Does the Altium Viewer Open?

The viewer is more flexible than its name suggests. It opens native Altium documents and several common interchange formats:

So if a client sends EAGLE files, a fab house sends Gerbers, or a colleague shares a KiCad project, you can usually open all of them in one place without installing three different programs.

What You Can See and Do in the Altium Viewer

Once a design is loaded, the viewer gives you the same core views an engineer uses to review a board:

• Schematic — navigate sheets, inspect symbols, nets, and designators.
• PCB layout (2D) — toggle layers, view traces, pads, planes, and silkscreen.
• 3D view — see the assembled board with component bodies, height, and clearances.
• Bill of materials — review the BOM tied to the design.
• Cross-probing — click a part in the schematic and find it on the PCB (and vice-versa).
• Layer stack — examine the stackup definition.
• Measurement — measure distances and clearances on the layout.

That set is enough to answer most “what is on this board?” questions: footprint choices, component placement, layer count, net connectivity, and mechanical fit.

Altium Viewer: Web, Standalone, and Embedded Versions

Altium offers the viewer in more than one form:

• Web (Altium 365 Viewer) — runs in the browser, nothing to install; the most common way to use it.
• Standalone Altium 365 Viewer — a desktop application for those who prefer a local app.
• Embedded “Web Viewer” — the same viewing engine that can be embedded into a web page so designs can be shown in context.

All three present the design read-only; the difference is where the window lives.

How to Use the Altium 365 Viewer: Step by Step

1. Open the Altium 365 Viewer in a current web browser.
2. Sign in with a free Altium account (required to upload and view).
3. Upload your file — drag in the Altium, EAGLE, Gerber, ODB++, or KiCad data.
4. Choose a view — schematic, 2D PCB, 3D, or BOM, and toggle layers as needed.
5. Inspect — cross-probe parts, check the layer stack, and measure clearances.
6. Share or close — send a view link to a colleague or supplier, or simply close the tab. Uploaded designs are removed when the browser tab is closed unless you have deliberately shared them.

What the Altium Viewer Cannot Do

• No editing. The viewer is strictly read-only — you cannot move parts, route, or change the BOM. For edits you need Altium Designer or the original CAD tool.
• Account required. Uploading and viewing requires signing in with a free account.
• Not a manufacturing sign-off. Seeing layers render correctly is not the same as confirming the board is manufacturable; that needs a DFM check against a fab’s capabilities.
• Beta caveats. Some format support (KiCad) is marked beta and can change, so verify behavior with your specific files.

Altium Viewer vs Other Free PCB Viewers

The Altium 365 Viewer is strongest when you want schematic + PCB + 3D + BOM from native CAD files in one browser tab. If your job is narrower — say, just checking fabrication Gerbers — a dedicated Gerber viewer may be quicker.

For a side-by-side of free Gerber-specific tools, see our companion guide on Gerber viewers.

How to Review a PCB Design You Didn’t Create

A viewer is most often used to inspect a design someone else made — a contractor’s layout, a supplier’s board, or a file handed over at acquisition. A quick, repeatable pass turns “I can see it” into “I understand it”:

1. Layer count and stackup — open the layer stack to confirm it matches what you expect (and what you’ll pay to fabricate).
2. Board outline and size — measure the overall dimensions and check mounting holes against the mechanical envelope.
3. 3D fit — switch to 3D and look for tall parts, connector positions, and anything that could clash with an enclosure.
4. Critical nets — cross-probe power, ground, and any high-speed or RF nets from the schematic to the PCB to see how they’re routed.
5. Component choices — scan the BOM for parts that are obsolete, single-sourced, or long-lead.
6. Silkscreen and polarity — confirm reference designators, pin-one marks, and polarity indicators are present and legible.
7. Obvious red flags — traces hugging the board edge, missing ground stitching, or copper where a keep-out should be.

This pass won’t replace a manufacturability review, but it tells you quickly whether a design is in good shape or needs questions answered before you commit.

Viewing a Design vs a Manufacturability (DFM) Check

A viewer answers “what does this design contain?” It does not answer “will this board build correctly at my chosen line width, drill size, and stackup?” Those are different questions. Rendering Gerbers cleanly tells you the data parses; it does not flag a trace too close to a board edge, an annular ring below the fab’s minimum, an acid trap, or an unrealistic impedance target. That is the job of a design-for-manufacturing review against a real factory’s capabilities — which is the step that prevents a design that “looks fine in the viewer” from failing in fabrication.

Highleap’s Free Gerber and 3D Viewers and DFM

Highleap Electronics, a China-based PCB and PCBA manufacturer, provides free in-browser tools so you can check your data before quoting, and backs them with an engineering review:

• Online Gerber viewer — load and inspect fabrication layers directly in the browser.
• 3D viewer — preview the assembled board’s mechanical form.
• DFM review — a manufacturability check that catches clearance, annular-ring, drill, and stackup issues a viewer cannot.
• PCB fabrication and assembly once the data is confirmed buildable.

Altium Viewer FAQ

Is the Altium Viewer free?

Yes. The Altium 365 Viewer is free to use; you sign in with a free account, upload a design, and view it in the browser. You do not need a paid Altium Designer license to view.

Can the Altium Viewer open files other than Altium’s?

Yes. Besides native Altium schematic and PCB files, it opens EAGLE (.SCH/.BRD), Gerber (RS-274X and X2), ODB++, and — in beta — KiCad files, which makes it useful as a general-purpose design viewer.

Can I edit a board in the Altium Viewer?

No. It is read-only. You can view, navigate, cross-probe, measure, and share, but to change the design you need Altium Designer or the CAD tool the file came from.

Do I need to install anything?

For the web version, no — it runs in a modern browser. There is also a standalone desktop viewer and an embeddable web viewer if you prefer those, but installation is optional.

Is my design kept private?

Uploaded designs are removed when you close the browser tab unless you deliberately share them via a link. Treat any shared link as you would any shared file, and follow your own confidentiality requirements for sensitive designs.

Is viewing my Gerbers enough to confirm the board is manufacturable?

No. A viewer confirms the data renders and lets you inspect it, but manufacturability depends on matching your design to a fab’s minimum line/space, annular ring, drill, and stackup capabilities. Run a DFM review for that assurance.

What is the difference between the Altium Viewer and a Gerber viewer?

The Altium Viewer reads native CAD files (Altium, EAGLE, KiCad) and shows schematic, PCB, 3D, and BOM together, in addition to Gerber/ODB++. A dedicated Gerber viewer focuses only on fabrication output layers, which can be faster if Gerbers are all you need to check.

Can I open a .PcbDoc file without Altium Designer?

Yes. Upload the .PcbDoc to the free Altium 365 Viewer in your browser and you can view the PCB in 2D and 3D, toggle layers, cross-probe, and measure — with no Altium Designer license. The only limit is that you cannot edit the design.