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 Outdated schemas are automatically flagged by the validator.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

BIM Best Practices · 2026-04-22 · 5 min

IFC Health Score: The Single Number Your BIM Team Needs

What is an IFC Health Score, how is it calculated, and why should every project BEP specify a minimum threshold before CDE delivery?

IFC Health Score: The Single Number Your BIM Team Needs — IFC Viewer Online article cover

A Health Score is a single 0–100 number that summarises the structural and data quality of an IFC file. Think of it like a credit score for your model: below 60 means serious problems, 60–80 means needs attention before coordination, 80+ means ready for CDE delivery.

How It's Calculated

The score uses a logarithmic penalty model: each validation issue subtracts points from 100, but the penalty diminishes with scale. A model with 1,000 duplicate GUID errors is penalised more than one with 10, but not 100× more — this prevents a large, dense model from looking arbitrarily worse than a small, sparse one for the same underlying problem density.

Issue severity is weighted: schema errors carry 3× the penalty of warnings, which carry 3× the penalty of info checks. The final score is calculated per-model and aggregated when multiple models are open.

What Score Should You Require?

≥ 90 — Design development and LOD 300+ coordination deliveries.
≥ 80 — Standard BIM coordination and CDE uploads.
≥ 70 — Concept design and LOD 200 exchanges.
< 60 — Not suitable for any formal CDE delivery.

Why a Single Number Matters

Detailed validation reports — 400 issues across 12 rule categories — are invaluable for fixing problems. But they're not useful for tracking progress over time or communicating quality to stakeholders who don't work in IFC files.

A Health Score creates a shared reference point that everyone understands: the model is at 73, we need it at 80 before coordination. It turns model quality from a vague aspiration into a measurable deliverable criterion.

IFC Health Score: The Single Number Your BIM Team Needs