> For the complete documentation index, see [llms.txt](https://doc.duaer.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.duaer.com/build/summarize.md).

# Summarize fields in Duaer

In Duaer, Summarize sets Aggregation (default Count) and Field under Fields to Summarize. Use Fields to Split By to group.
## Count values in a field

1. Search for Summarize and connect it after a node that returns many items.
2. Under Fields to Summarize, leave Aggregation on Count and set Field to the field name.
3. To group, set Fields to Split By, for example country.
4. Select Execute step. The output is the summarized items.

Aggregation can also be Append, Average, Concatenate, Count Unique, Max, Min, or Sum.

Output Format under Options defaults to Each Split in a Separate Item. With All Splits in a Single Item, the group field label is Fields to Group By.
## Questions

### When do I use Summarize vs Aggregate in Duaer?

Summarize counts, sums, and groups. Aggregate packs items into lists or collected fields. Use Summarize for stats; use Aggregate to bundle items.