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 Outdated schemas are automatically flagged by the validator.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

Tool Guides · 2026-04-10 · 7 min

How to Export Clean IFC Files from Revit: A Step-by-Step Guide

Revit's default IFC export settings produce avoidable validation warnings by the dozen. Here are the exact settings that eliminate the most common failures before the file reaches the CDE.

How to Export Clean IFC Files from Revit: A Step-by-Step Guide — IFC Viewer Online article cover

Revit has supported IFC export since 2012, but the default settings are optimized for the widest compatibility with receiving software — not for quality. This means they make conservative choices that create validation warnings by the dozen. Here's how to change that.

Step 1: Use the Open Source IFC Exporter

Autodesk's built-in IFC exporter is functional but lags behind the community-maintained open source version. The open source exporter (free on the Autodesk App Store) generates cleaner GUIDs, better spatial hierarchies, and properly supports IFC4. Install it before configuring any export settings.

Step 2: Choose the Right IFC Version

Unless your project specification explicitly requires IFC2x3, export to IFC4 Reference View. IFC4 is the current ISO standard, produces smaller file sizes for complex geometry via tessellated meshes, and resolves several structural ambiguities present in the older schema.

Step 3: Configure These Settings

"Export GUIDs": set to "Keep Existing". Never "Generate New" — this breaks BCF cross-references on every re-export.
"Site Placement": set to "Shared Coordinates". Prevents elements from being placed 10 km from the WCS origin.
"Include Steel Connections": Off (unless delivering a structural steel model).
"Export Base Quantities": On for LOD 200+ deliveries.
"Split Walls and Columns by Level": On. Ensures walls are associated with individual storeys.

Common Revit-Specific Issues After Export

Proxy overuse: Revit families without an IFC mapping export as IfcBuildingElementProxy. Map common families to proper IFC classes in the export mapping table.
Coordinate offset: Verify the project shares coordinates with the survey point before export.
Missing property sets: Revit properties export as custom Psets by default. Review the Pset mapping to ensure required standard Psets are included.

How to Export Clean IFC Files from Revit: A Step-by-Step Guide