How to Debug n8n Executions and Data Problems

Debugging in n8n is mostly looking carefully at data.

Start with the execution

Open the executions list, find the failed run and click it. The canvas shows which node failed, with its error message.

Check the data going into the failing node. Often a field is missing, empty or named differently than you expected.

Pinning keeps sample output from a node so you can build later nodes without calling the app each time.

Execute one node at a time and compare results with what you expect.

Disconnect parts of the workflow or copy the problem into a small test workflow.

Expressions with wrong field names (expressions and JSON), expired credentials, API limits and empty lists.

Error messages often name the exact problem. Search for the message with the app’s name if unclear.

Add checks and alerts: error workflows.

Open the failed execution and check the highlighted node.

Saving sample output so you can build without repeated calls.

Wrong field names, expired credentials, limits and empty lists.