Unexpected Behavior in n8n Switch Node with Empty String Conditions

Based on your description, one common source of this behavior is the switch node’s configuration option that allows multiple outputs to run if more than one condition evaluates to true. In n8n, if the switch node is set to output all matching branches rather than stopping after the first match, then it may end up triggering both the “is empty” and “is not empty” branches when the evaluation isn’t mutually exclusive.

What to Check

• All Matching Outputs Option
  Verify whether your switch node is configured with the option to execute all matching outputs. In some configurations (for instance in workflows where multiple branches may execute), n8n can run more than one branch if they all evaluate as true. If you intend only one branch to run, make sure that the switch node is set to execute only the first matching branch.

• Condition Definitions
  Confirm that the conditions for “is empty” and “is not empty” are set up correctly for your string value. For example, if you’re using expressions, ensure that the value isn’t being coerced or misinterpreted (e.g., with whitespace or undefined values).

• Data Integrity
  Double-check that the string you’re testing is defined as expected. If the property is missing from the incoming JSON, that might lead to unexpected behavior in your conditions.

Next Steps for Troubleshooting

1. Review the Switch Node Settings:
   Open your switch node configuration and look for any option similar to “All Matching Outputs” or similar wording. If it’s enabled, disable it to enforce mutually exclusive branching.

2. Test with Different Inputs:
   Use simple test cases (an empty string vs. a non-empty string) to see whether the behavior persists. This can help you confirm that the issue is with branch selection rather than the data.

3. Adjust Conditions If Needed:
   Make sure that your “is not empty” branch only evaluates as true when there’s a valid string, and that “is empty” correctly captures the case where the string is strictly empty (or undefined if that’s your intention).

Let me know if this helps or if you need further clarification on any part of the configuration.