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 Outdated schemas are automatically flagged by the validator.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

Best Practices · 2026-06-04 · 9 min

GDPR and BIM Data: What Every Project Manager Needs to Know (2026)

IFC files can contain personal data under GDPR. Sharing a model with a subcontractor via a cloud tool creates data processing obligations with legal teeth. Here's what EU project teams need to understand before the next BIM delivery.

GDPR and BIM Data: What Every Project Manager Needs to Know (2026) — IFC Viewer Online article cover

GDPR is not just an IT department problem. It applies to any team that handles information about identifiable people — and on a construction project, that can mean BIM coordinators, project managers, and delivery teams.

This guide covers three things: when IFC data is actually personal data under GDPR, what happens legally when you use a cloud BIM tool to process it, and how to choose tools that remove the compliance overhead entirely.

When Is an IFC File Personal Data?

GDPR Article 4 defines personal data as any information relating to an identified or identifiable natural person. Most IFC files don't contain personal data in the obvious sense — they describe buildings, not people. But edge cases are more common than teams realise:

IfcSpace elements named after occupants ('Dr. Smith's Office', 'Johnson Suite') can constitute personal data if the name identifies a living natural person.
IfcActor and IfcPerson entities — if your model includes responsible persons (project manager, BIM coordinator) with names and contact details, those are personal data.
Photos embedded as IfcDocumentInformation — images of workers on-site included in design documentation.
Access control data attached to security-relevant spaces — information about who is authorised to enter a specific room.

The Legal Structure: Controller, Processor, and Article 28

When you use a cloud BIM tool that processes IFC files on its servers, two GDPR roles are created. You (or your organisation) are the data controller — you determine the purpose of processing. The tool vendor is a data processor — they act on your behalf. GDPR Article 28 requires a written Data Processing Agreement (DPA) between you and every processor before you share personal data with them.

In practice: if your project IFC contains personal data (IfcPerson entries, named spaces, embedded photos) and you upload it to a cloud BIM viewer, you need a DPA with that vendor. Many small BIM tool vendors don't have DPAs readily available — meaning you're technically in breach of GDPR the moment you upload.

How Client-Side Processing Eliminates the Problem

Tools that process IFC files entirely in the browser never receive the model data. If model data never reaches a server, there is no data processing event under GDPR for the model content — no controller-processor relationship, no DPA to negotiate, no data residency decision, no breach notification obligation.

This is the practical reason why browser-native processing matters for B2B projects: it removes an entire compliance category before the project even begins.

Local validation before CDE upload

Run a health check before uploading to the CDE. No third-party data processing — you stay the sole data controller throughout.

Sharing a validation report

Share a report URL containing issue summaries only — no model geometry, no personal data from the IFC.

Cloud BIM viewer

Model uploaded to vendor servers. If it contains personal data, you need a DPA and a data residency decision before upload.

Coordination platform (ACC, BIM 360)

Autodesk provides a DPA as part of their Terms of Service — verify it covers your project data categories and storage region.

Six Questions to Ask Any BIM Tool Vendor

Is model data processed locally on the user's device, or uploaded to your servers?
If uploaded: where are your servers located? (EU data residency matters for GDPR)
Do you have a Data Processing Agreement (DPA) available for GDPR Article 28 compliance?
What data do you retain after the user closes the session?
Who are your sub-processors (infrastructure, analytics, storage)?
Are you ISO 27001 or SOC 2 Type II certified?

IFC Viewer Online: GDPR at a Glance

No model upload

IFC files parsed by WebAssembly running in your browser. Nothing reaches our servers. No DPA required for model data.

Cookieless analytics

Anonymous usage events via PostHog in memory-only mode — no tracking cookies set. Legal basis: legitimate interest.

Email by consent only

Collected only with explicit opt-in. Processed via Resend. Unsubscribe at any time.

Shared reports are opt-in

Issue summaries only — no model geometry, no personal data from the IFC file. You decide when to share.

Browser-native processing removes an entire category of GDPR compliance obligation: there is no data controller-processor relationship to manage when the model never reaches a server.

For formal vendor assessments, the full Privacy Policy documents every data flow in plain English, including the legal basis for each processing activity.

GDPR and BIM Data: What Every Project Manager Needs to Know (2026)