# Loops and Batches — AI Automation with n8n

Source: https://www.geekswithgeeks.com/en/n8n-ai-automation/data-loops-batches

> Process many items in batches to respect API limits.

## Do not hammer the API

By default a node processes all items quickly, which may hit a service's **rate limit**. The **Loop Over Items** (Split in Batches) node feeds items in groups, for example 10 at a time; add a **Wait** node inside the loop to pause between batches. Most nodes also have batching and retry settings under their options.

## Batching arithmetic

This chunk function ran in Node.js and shows what a batch size of 2 does to 5 items: three groups, the last one smaller.

```javascript
function chunk(arr, n) {
  const r = [];
  for (let i = 0; i < arr.length; i += n) r.push(arr.slice(i, i + n));
  return r;
}
console.log(JSON.stringify(chunk([1, 2, 3, 4, 5], 2)));
```

Output:

```
[[1,2],[3,4],[5]]
```

**Quiz:** Why process items in batches with a Wait node?

- [x] To stay within an API's rate limit
- [ ] To make data larger
- [ ] Because n8n forbids loops
- [ ] To hide errors

*Answer:* To stay within an API's rate limit. Spacing out calls prevents 429 errors from services with request limits.