# How do I add my models to a check?

Drop up to five IFC files on the Check page, anywhere on it, or click the mark to choose them. They are listed under Files, where you can add more, remove one or clear them all. A sixth model is not added, and a very large model gets a warning but is still checked.

Updated 1 November 2026

## Add models, step by step

1. Open **Check** in the top bar.
2. Drag your `.ifc` files from your folder and drop them on the IFC Checker mark, or anywhere on the page.
3. Or click the mark and choose the files in the dialog that opens: **Choose files**.
4. Read the list under **Files**. Each model has a row with its name, its IFC schema, its size and a bar that fills while the file is read.
5. To add more, drop them anywhere on the page, or choose **Add files**. A check takes up to five models.
6. To take one away, choose the small ✕ at the left of its row. To take all of them away, choose **Clear all**.
7. Pick a test, or tick **Model health**, then choose **Run checker** ([How do I pick a test?](https://ifcchecker.com/help/pick-a-test/)).

## Up to five models

One check takes up to five models and checks them one after another against the same test. All of them show on one Results page, with one index for all of them. When a sixth is dropped, the first five are kept and the notice names each of the others as not added. Models of one project, for example architecture, structure and services, are the natural set.

## The same file again

A model added again under a file name that is already listed takes the place of that one and does not count again. This is also what happens when you export the model from your authoring tool again after fixing it, and add the new file: the old row is replaced, and the test you picked stays picked. Under another file name the new file is added beside the old one, so remove the old one first.

## A very large model

**A check of a model over 500 MB may run out of memory.** A model over 500 MB is still added, with a warning above the tests that gives its size, one line for each such model. If its check does not finish, export a smaller part of the model from your authoring tool, for example one building, one storey or one discipline, and check the parts together.

## A file that is not added

Check takes IFC files in the STEP format, and IDS files. Any other file is not added, and the notice says so after its name. [Why was my file refused or not read?](https://ifcchecker.com/help/troubleshooting-file-refused/)

## Keep reading

Next: [How do I try the sample model?](https://ifcchecker.com/help/try-the-sample/)

Related:

- [What is on the main screen?](https://ifcchecker.com/help/main-screen/)
- [How do I pick a test?](https://ifcchecker.com/help/pick-a-test/)
- [Why was my file refused or not read?](https://ifcchecker.com/help/troubleshooting-file-refused/)

[Workflows and help](https://ifcchecker.com/help/) / [Adding models](https://ifcchecker.com/help/collections/models/)