How to setup the TestFit Add-in for Revit
Setup
Sign in and go to the Downloads page at app.testfit.io/downloads. Then scroll to the bottom, you should see the TestFit Addin for Revit. Click on the three dots and click Download.
Once downloaded, run the .msi file and complete the steps when asked.
You've installed the TestFit Add-in for Revit. Once you open Revit, you'll see the TestFit tab on the top of the program. To import a TestFit site into Revit, continue with the Importing TestFit into Revit knowledge base article.
NOTE: Revit LT does not support add-ins, therefore the TestFit Add-in for Revit only works for regular Revit versions 2018 through 2025.