Is my IFC file uploaded anywhere?

No. Files are parsed entirely in your browser via web-ifc, a WebAssembly build of the open-source IFC parser. Nothing leaves your machine. The app works completely offline once loaded.

Can I use it with confidential models under NDA?

Yes. Because all processing happens in your browser and no data is ever transmitted to any server, you can safely use it with confidential project models under NDA. There is no service agreement to review with your client — no data changes hands.

Can I share the validation results with my team or client?

Yes. After running validation, click Share Report to copy a link that encodes the full Health Score and issue list directly in the URL — no file upload, no server, no account required. You can also export results as JSON, CSV, or a Validation Certificate. The IFC file itself never leaves your browser.

Yes, fully. IFC Viewer Online works on any modern browser — Chrome, Edge, Firefox, and Safari on both Mac and Windows. No plugin, no installation, no operating system restriction.

What happens if my IFC file is very large?

The app handles files up to 2 GB. Performance depends on your device — files under 200 MB load well on most modern hardware. Once parsed, geometry is cached in OPFS so every subsequent load of the same file is instant, even offline.

How does the validation work?

The validator runs 44 built-in rules in a background Web Worker so the UI stays responsive. Rules cover GUID duplicates, spatial hierarchy, orphan elements, naming conventions, missing type assignments, ISO 19650 property sets, LOD completeness, clash detection, proxy overuse, coordinate offset, storey-elevation integrity, unit consistency, and more. You can also run a buildingSMART IDS specification against the model. Every model receives a Health Score from 0 to 100. Results stream in as each rule completes.

Can I fix errors and re-export a corrected IFC?

Yes. All edits (GUID fixes, renames, property value changes) are held as non-destructive diffs with full undo/redo. Clicking Export IFC applies all diffs to the original binary in a Web Worker and downloads the corrected file — no server involved.

What IFC versions are supported?

IFC2x3, IFC4, IFC4x1, and IFC4x3. The viewer uses the open-source web-ifc parser — the same engine used by most modern BIM tools and @thatopen/components. Outdated schemas are automatically flagged by the validator.

What measurement tools are available?

You can measure lengths between any two points, areas of surfaces, volumes of enclosed elements, and individual edge lengths — all directly in the 3D viewport. Measurements persist as labelled annotations and can be exported alongside your model.

Can I load multiple IFC files at once?

Yes. Load as many IFC files as your device memory allows. Each model has independent visibility, transforms, validation, quantity takeoff, and export. Use the Scene panel to manage, reorder, or remove models at any time.

Does it work offline?

Yes, once the page is loaded. The WebAssembly parser and WebGL renderer run entirely in the browser. Parsed geometry is cached in OPFS so repeat loads are instant even without a network connection.

What are the file size limits?

There is no enforced limit — performance depends on your device. Files up to ~200 MB typically load well on modern hardware. The OPFS geometry cache means you only pay the parse cost once per file.

Is it free? Can I use it for commercial projects?

Yes, completely free. The source code is MIT-licensed. You can use the live app or fork the repository for your own projects, including commercial ones.

Back to the BIM & IFC blog

IFC Tips · 2026-06-03 · 8 min

Revit ↔ Archicad via IFC: The Round-Trip Problems Nobody Warns You About

You link an Archicad IFC into Revit and find duplicate geometry floating hundreds of feet in the air — even though the same file looks perfect in the cloud viewer. Cross-tool IFC exchange has failure modes that only show up between vendors. Here's what breaks and how to work around it.

Revit ↔ Archicad via IFC: The Round-Trip Problems Nobody Warns You About — IFC Viewer Online article cover

IFC is supposed to make tool choice irrelevant — the architect uses Archicad, the engineer uses Revit, and the open format bridges them. In practice, the Revit ↔ Archicad exchange has failure modes that only appear when you cross vendors, and they cause real coordination headaches because the file looks fine right up until it doesn't.

Random duplicates of geometry, suspended hundreds of feet in the air — even though the IFC displays correctly in the online viewer.
Autodesk Community — Revit & Archicad interoperability

The Symptom: It Looks Fine in One Tool, Broken in Another

The most reported failure: an Archicad IFC links into Revit with phantom duplicate geometry, sometimes displaced far from the model — yet the exact same file renders perfectly in a cloud viewer. This is the key diagnostic clue. When a file is correct in one tool and broken in another, the file is usually fine; the importer is interpreting it differently.

What Actually Goes Wrong

Import interpretation differences: each vendor's importer rebuilds geometry from the IFC representation its own way. Representations that are valid but unusual (certain swept solids, mapped items) can be doubled or misplaced by a different tool's importer.
Open vs Link: opening an Archicad IFC in Revit forces a conversion to native elements that mangles complex geometry. Linking uses the reference framework and stays clean — link, don't open.
Source matters: the same IFC linked from a desktop folder versus from a cloud/CDE folder can produce different results, because the resolver path differs.
GlobalId and mapping mismatches: Archicad and Revit don't always agree on how source elements map to IFC classes, which surfaces as type or identity drift across the round trip.

How to Make the Exchange Reliable

Agree the IFC schema and MVD up front (IFC4 Reference View is a good cross-tool default).
On the Archicad side, enable stable GlobalIDs and a clean translator preset matched to the receiving tool.
On the Revit side, link the IFC — never open/import it for coordination.
Validate the IFC in a neutral viewer before linking, so you know whether a fault is in the file or the importer.
If duplicates appear only in Revit, try linking from a local copy and check the import settings rather than blaming the export.

Use a neutral viewer as the referee

Open the cross-tool IFC here first. If it's clean in this viewer but broken after linking into Revit, you've isolated the problem to the importer — not the file.

IFC2x3 · 2.4 MB

Open the interactive IFC viewer

Cross-tool exchange is one slice of overall model quality — for the complete pre-delivery framework see The Complete Guide to IFC Quality, and for stable identities across the round trip see Why IFC GUIDs Change on Every Export.

Revit ↔ Archicad via IFC: The Round-Trip Problems Nobody Warns You About