> For the complete documentation index, see [llms.txt](https://docs.keyfax.biz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.keyfax.biz/product-suite/admin/entities/databoxes/testing-databoxes-and-expressions.md).
# Testing Databoxes & Expressions
Ensuring everything works as expected!
Expressions can be created against all types of Databox except Company Data (aka Fixed Text).
Wherever you create Expressions, a Test facility is provided. In essence, it will allow you to evaluate what happens when certain data is encountered by the Databox.
When you click **Test** (in the Editing pane, not the main menu) a popup window will appear where you can supply a value for the Databox by entering a value. Then click **Evaluate**.
Any errors will be reported but, if all is well, you will see the results of the Expressions:
Testing your Expressions
### Here's an idea...
You might find that it's a useful idea to have a 'scratch' Databox whose only purpose is to house a number of example Expressions which you can use to test and confirm that the (sometimes esoteric!) formatting is correct. Here's such a random selection:
