IFC Schema & Identity Check

Verify the IFC schema version and element identity — flags duplicate GlobalIds, missing identifiers, and unexpected schema versions. Run it on its own, or stack it with other checks in the Validation Center.

Check an IFC model's identity layer online: every element's GlobalId is present and unique, and the schema version is one that downstream tools can actually process. Upload the model, run the check, and get the offending elements listed by GUID.

This is the least glamorous check in the set and the one whose failures cost the most, because everything else quietly assumes it passed. A GlobalId is an IFC element's permanent identity — it is how a clash result names an element, how a BCF issue points at one, how a federation tells two models' elements apart, and how any version comparison decides whether an element is new, moved or deleted. A single duplicated GUID doesn't produce an error anywhere; it produces wrong answers everywhere, silently.

When to reach for it: Before federating or running IDS / clash checks that assume unique identifiers. Duplicate GlobalIds silently break selection, colouring, and BCF round-trips; an unexpected schema version breaks validators that only accept IFC4.

What you get: A findings list of duplicate GlobalIds and elements with missing identifiers, plus the model's detected schema version — exportable to BCF, HTML, or CSV.

Example: Catch duplicate GUIDs and confirm you're on the IFC schema version your downstream tools expect.

Why duplicate GUIDs are reported as critical

Duplicates and missing identifiers are the only findings in the whole validation catalogue rated critical, and the reason is that they corrupt results rather than describing a fault. A comparison between two revisions matches elements by GlobalId; if two elements share one, the comparison reports a change that didn't happen or misses one that did. A BCF issue referencing a duplicated GUID resolves to whichever element the receiving tool happened to index first, so the recipient opens the wrong element and reasonably concludes the issue is nonsense.

Duplicates most often arrive from a copy-paste in the authoring tool, a family or component duplicated without regenerating its identity, a merge performed by concatenating files, or an exporter bug. None of those announce themselves. The check lists every affected element by GUID, so the fix is targeted rather than a full re-export.

Schema version, and why the addendum matters

The check also reports the schema the file declares. IFC2x3 and IFC4 are processed by everything here. IFC4x3 — the infrastructure schema — opens and runs the data-side tools, and the specific addendum in the file header is load-bearing rather than cosmetic: a file declaring IFC4X3_ADD2 opens, while one declaring IFC4X3_TC1 (the ISO 16739-1:2024 label, which does appear in the wild) does not, on the same geometry. Knowing which token your file carries is the difference between "this tool is broken" and "convert this first".

If the schema is the problem rather than the identity, Upgrade IFC and Downgrade IFC convert between IFC2x3, IFC4 and IFC4X3 by rebuilding every entity in the target schema.

Findings you can act on

Every finding carries the element GUID, which is what makes it repairable rather than informational. The Repair Center reads the same findings and can regenerate conflicting identifiers, and results export to HTML, CSV or BCF so a GUID problem in a consultant's model can be raised as an issue against the model rather than described in an email.

Run this before anything that depends on identity — before a federation, before a revision comparison, before issuing a model for coordination. Stack it with the other atomic checks in the Validation Center to get the whole picture in one pass.

How to check IFC GlobalIds and schema version

Upload your IFC file
Click Run — no configuration needed
Review flagged duplicate or missing GlobalIds and the detected schema version
Export to BCF, HTML, or CSV

Under the hood

BIMCamel parses IFC files in the browser using the open-source web-ifc engine and renders models with @thatopen/components + three.js. Heavy operations (clean / optimise / validate / convert) run on disposable server-side workers using the same web-ifc stack plus our own .NET pipeline; results stream back to your browser as soon as they're ready. Uploads sit on our servers only as long as your tier's retention window allows and are never used to train AI.

Frequently asked questions

How do I find duplicate GlobalIds in an IFC file?

Upload the model and run this check. It tests every IfcRoot for a present and unique GlobalId and lists every offending element by GUID, so you can fix the specific elements rather than re-exporting the whole model.

Why are duplicate GUIDs treated as critical?

Because they corrupt results instead of producing errors. Clash reporting, BCF issues, federation and revision comparison all identify elements by GlobalId — a duplicate makes a comparison report changes that didn't happen and makes a BCF issue open the wrong element, with nothing anywhere reporting a fault.

What causes duplicate GUIDs?

Usually a copy-paste in the authoring tool, a component duplicated without regenerating its identity, a merge done by concatenating files, or an exporter bug. None of them announce themselves, which is why the check exists.

Which IFC schema versions does it accept?

It reports whatever the file declares. IFC2x3 and IFC4 are fully processed; IFC4x3 opens and runs the data-side tools, and the addendum matters — IFC4X3_ADD2 opens while IFC4X3_TC1 does not. Use Upgrade IFC or Downgrade IFC to convert between schemas.

Can I fix the problems it finds?

Yes — the Repair Center reads the same findings and can regenerate conflicting identifiers. You can also export the findings as HTML, CSV or BCF to raise them against whoever owns the model.

What's the maximum IFC file size?

Up to 25 MB as a guest, 100 MB with a free account, 500 MB on Pro, and 1 GB on Team. The caps are on upload size only — every tool itself is available on every tier.

What happens to my file after processing?

Your file is uploaded over HTTPS and processed on our servers. Guest uploads are stream-only — the working files are deleted as soon as your download finishes. Free accounts keep results for 7 days; Pro keeps them 90 days and Team 180 days. Files are never shared with third parties or used to train AI.

Is IFC Schema & Identity Check free?

Yes. IFC Schema & Identity Check is free to use — guests get 3 runs a day with 25 MB uploads, and a free account raises that to 10 runs a day with 100 MB uploads. No trial clock, no watermarks.