Split in Batches

Work through a list a few items at a time, running the same steps once per batch.

What it does

Split in Batches works like Loop, but instead of a condition you give it a list. It has two inputs and two outputs:

• Input (top): where the data first comes in.
• Loop Back (bottom input): connect the last step of the repeated part here.
• Loop (output): gets the next batch; the steps to repeat start here.
• Done (output): runs once, after the last batch.

On each pass it sends the next Batch size items out of Loop and waits for them to come back through Loop Back before sending the next ones. With 7 items and a batch size of 3, the steps run three times, with items 1-3, 4-6 and 7, then the workflow continues from Done.

• An empty list goes straight to Done. A single value that is not a list counts as one batch of one item.
• As a safety limit, the node stops after 1,000 passes, even if items are left.
• If the run pauses in the middle (for example on a Wait For Approval inside the loop), it resumes at the right batch.

When to use it

• Send rows to an API 10 at a time because it rejects large requests.
• Ask for an approval or show a form once per item (batch size 1).
• Slow down: add a Wait inside the loop so a site or API isn’t hit too fast.

Most nodes already run once per item, so you don’t need Split in Batches just to handle every item of a list. To repeat until a condition changes, use Loop.

Inputs and settings

Setting	Type	What it does
Items REQ(required)	Value	The list to split into batches.
Batch size	Number	How many items to emit per pass. Default: 1

Set Items to an expression that returns a list, for example {{ $input.data.contacts }} after an Http Request. If your data arrives as many separate items, gather them into one list first with Aggregate.

Outputs

• Done
• Loop

Each output item has these fields:

Field	Type	What it holds
done	True/false	True once every item has been emitted
batch	List	The items of this pass
batchIndex	Number
isLast	True/false
items	List	Every item being split

Shape of an output item

{
  "done": true,
  "batch": [],
  "batchIndex": 0,
  "isLast": true,
  "items": []
}

In the repeated steps, read the current batch with {{ $input.batch }}. batchIndex counts batches from 0, and isLast is true on the final batch. From Done, {{ $input.items }} still gives you the whole list.

Dependencies and credentials

None. This node needs no connection and has no slots for other nodes.

Example workflow

Send contacts to an API 25 at a time:

1. Http Request gets https://api.example.com/contacts, which returns { "contacts": [...] }.
2. Split in Batches with Items {{ $input.data.contacts }} and Batch size 25.
3. From Loop: a second Http Request, POST to https://api.example.com/contacts/bulk with {{ $input.batch }} in the JSON body, then Wait with Amount 2 and Unit Seconds. Connect the Wait to Loop Back.
4. From Done: Show Notification says All contacts sent.

Common issues

• The steps run only once. The last repeated step is not connected to Loop Back, so the node never gets asked for the next batch. Connect it to the bottom input, not the top one.
• It goes straight to Done. Items resolved to an empty list or to nothing. Check the expression in the run’s input for this node; it must point to a list.
• Nothing runs after the loop. Connect the next steps to Done, not to Loop.
• It stopped before the end of a very long list. The node stops after 1,000 passes. Raise Batch size so the list fits in fewer passes.

Related nodes

• Loop: repeat while a condition holds.
• Split Out: turn a list field into separate items, without looping.
• Wait: pause between batches.
• Aggregate: gather items back into one list.