n8n Loops

Three meanings of "loop" map to three mechanisms:

1. "Run this node for every item." Default. Most nodes loop automatically, so do nothing.
2. "Run this node once with all items, not once per item." The executeOnce setting (single boolean).
3. "Process items in explicit batches with control flow between iterations." The Loop Over Items node (formerly Split In Batches).

For paginated APIs, the HTTP Request node has built-in pagination. Almost always preferable to a hand-built page-counting loop.

The model: items are an array

Data flows between nodes as an array of items, each { json: {...}, binary?: {...} }. 50 items = 50-entry array.

Default: a node runs once per item. An HTTP Request with 50 input items fires 50 requests and outputs 50 result items. This is the implicit loop most workflows rely on.

The input array is the loop. Control iteration by controlling the array.

Non-negotiable