Testing flows with the Flow Builder debugger
Key Takeaway
The Flow Builder debugger shows you how a flow runs and exactly where it fails. Unless you select "Run flow in rollback mode", a debug run performs the flow's actions for real.
The Flow Builder debugger runs a flow from inside Flow Builder so you can watch it step by step. You use it to test a flow before you activate it and to troubleshoot a flow that is not working.
Debug option or Test Mode
The tool you use to test a flow before activation depends on the flow type.
If the flow is an autolaunched or record-triggered flow...
You use Test Mode (Beta) instead of the debugger. You set up a test scenario with a triggering record or input values, and you can save the scenario to reuse it later.
If the flow is any other flow type...
You use the Debug option in Flow Builder.