Actually Works · Episode 34

05 / 38

Your n8n node runs once for every item you send it — not once, total.

n8n's real execution model: a node doesn't run once per workflow, it runs once per item in the array it receives. That's why an HTTP Request node on 40 rows makes 40 real calls, not one call with 40 rows in it — and why a workflow that "ran fine" on 3 test items can quietly rate-limit or blow through a bill at 300.

The exact clicks

  1. Open any node in your workflow and check its input — n8n shows it as a list of items, not one blob of data.
  2. Run the workflow with a small test set (2-3 items) and watch the node execute once per item in the Executions panel — this is normal, not a bug.
  3. Before an expensive or rate-limited step (an HTTP Request to a paid API, for example), add a Loop Over Items node — officially named 'Split in Batches' in n8n's own docs.
  4. Set the batch size on the Loop Over Items node to however many items you want processed together per pass, rather than one at a time.
  5. Wire the expensive node inside the loop, and any per-batch waiting (a Wait node, for a rate limit) inside the same loop.
  6. Test again with a larger set (dozens of items) to confirm the batching actually slows the expensive step down the way you intended.

What changes

  • This is standard, current n8n behavior — verified live this session against current n8n documentation and community threads on per-item execution.
  • The Loop Over Items node's current official name is 'Loop Over Items (Split in Batches)' per n8n's own docs (updated June 2026) — 'Split in Batches' alone is its older/internal name.
  • Per-item execution is the core of n8n's data model, not an edge case — every node in every workflow works this way, whether or not a Loop node is present.

What it will not do

  • This explains and manages per-item execution; it doesn't remove real per-call cost or rate limits — batching controls the pace, it doesn't make the calls free.
  • Batch size is a real tradeoff: too large risks hitting a rate limit anyway, too small barely helps — the right number depends on the specific API's own limits.
  • Test with a set close to your real production volume before trusting a workflow at scale — 3 test items behaving fine says nothing about 300.

Get the next one

One AI setup a week, straight to your inbox.

Also buildingAgently— the catalog for AI agents