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 Outdated schemas are automatically flagged by the validator.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 · 2026-06-03 · 8 min

Free Online IFC Viewers Compared (2026): Privacy, Size Limits & Features

There are a dozen free browser-based IFC viewers now, and they make very different trade-offs — some upload your file to a server, some cap out at 10 MB, some have no validation at all. Here's an honest comparison to help you pick the right one for the job.

Free Online IFC Viewers Compared (2026): Privacy, Size Limits & Features — IFC Viewer Online article cover

Free online IFC viewers have multiplied — you no longer need a £5,000 workstation to open an IFC. But 'free browser viewer' covers tools that work in fundamentally different ways, and the differences matter when the file is confidential, large, or needs checking rather than just looking at. This is a practical comparison of what to weigh up, not a leaderboard.

The Four Things That Actually Differ

Upload vs local

The biggest divide. Some viewers send your file to a server to process it; others parse it entirely in your browser. For confidential project data, server upload is often a hard no.

File size limit

Free tiers range from ~10 MB to ~500 MB or more. Many viewers that feel snappy on a demo choke on a real federated model.

Validation

Most viewers only display geometry. A few also check the model — duplicate GUIDs, spatial hierarchy, a quality score. This is the difference between looking and knowing.

Account & storage

Some require sign-up and store your models in the cloud (with quotas); others need no account and keep nothing.

The Landscape in 2026

Privacy-first, local viewers: parse the IFC client-side via WebAssembly, no upload, no account. Best for confidential files. (This viewer is in this category.)
Upload-based cloud viewers: process server-side, often with collaboration features and cloud storage, usually behind a sign-up and a free-tier quota.
Lightweight 'quick look' tools: open a small IFC fast with pan/zoom, but cap file size low and offer no property inspection or validation.
LCA / platform viewers: an IFC viewer bolted onto a larger product (e.g. carbon or estimating tools), generous on size but tied to that platform's workflow.

How to Choose for the Job in Front of You

Pick a private, local viewer when…

The file is confidential and can't be uploaded
You need to validate, not just look
You want a Health Score / quality report
You need to check the model against an IDS / BEP requirement
The model is large and you want convert-once caching
You don't want to create an account

A cloud / platform viewer may fit when…

You need persistent cloud storage of models
You want built-in multi-user collaboration
The viewer is part of a platform you already use
Sharing a hosted link with non-technical reviewers matters
File confidentiality is not a constraint

Where This Viewer Fits

This one is deliberately in the private/local camp: it parses IFC in your browser via WebAssembly (zero bytes uploaded, no account), handles files up to ~500 MB with convert-once caching, and — the part most free viewers skip — runs 44 validation rules and returns a Health Score. It goes further than most: drop a buildingSMART .ids file to check the model against contractual delivery requirements (all six IDS 1.0 facets, validated against the official test cases), coordinate issues with full BCF 2.1 / 3.0 import and export, and place a georeferenced model on a real-world 3D map (street, satellite or terrain) — all client-side, no API key, nothing uploaded. So it's not just 'can I see it', it's 'is it any good, does it meet the spec, and where does it sit'.

Try the local + validation approach

Open the buildingSMART duplex with no upload and no account, and see the Health Score appear automatically. Then drop in a file of your own to compare.

IFC2x3 · 2.4 MB

Open the interactive IFC viewer

Once you've picked a viewer, the next question is usually whether the model is actually deliverable — for that, see How to Validate an IFC File Before You Send It and The Complete Guide to IFC Quality.

Free Online IFC Viewers Compared (2026): Privacy, Size Limits & Features