n8n Summarize nodeConfigure Summarize in n8n.

Aggregation decides how the values of the field you want to summarize get combined into one result. Pick it first, because the other fields that appear depend on the method chosen.

• Sum, Average, Min and Max: the numeric methods, for amounts, quantities and scores.
• Count and Count Unique: how many values came in, and how many distinct ones.
• Append and Concatenate: keep the values themselves, as a list or as one joined string.

This is where the aggregation gets pointed at something. Field holds the name of an input field that you want to summarize, and it is typed as text rather than picked from a list, so the spelling has to match the incoming data exactly.

• Field: the name of an input field you want to summarize, entered as text (placeholder e.g. cost, hint: Enter the field name as text). The name goes in, not the value, so cost and not {{ $json.cost }}.

Some items arrive with the field present but blank. This toggle appears alongside the Append and Concatenate methods and settles what happens to those blanks.

• Include Empty Values: turned on, empty values take their place in the appended or concatenated result; left off, they are dropped from it.

Concatenating values glues them together, and Separator is what goes between them. The hint in the panel says it plainly: what to insert between values.

• Comma, Comma and Space: the two readable defaults for an inline list.
• New Line, Space, None: one value per line, a single space, or no separator at all.
• Other: opens the Custom Separator field.

Only the five separators in the dropdown are offered by default. Selecting the other value reveals this text field, where you type whatever the output actually needs.

• Custom Separator: free text, used in place of the dropdown choice once Separator is set to Other.

Left empty, the node returns one figure for the whole batch. Fields to Split By is the group by statement: it breaks the summary into separate results based on the values of other fields.

• Fields to Split By: the name of the input fields you want to split the summary by, entered as text, separated by commas for several of them (placeholder e.g. country, city).

By default, a field to summarize that appears in none of the items stops the node with an error. This option, added from the Options collection with Add option, replaces that error with a single empty item.

• Continue if Field Not Found: turned on, the node continues and returns one empty item; turned off, it keeps the default error behavior.

Nested data is the reason this option exists. n8n reads child fields in the parent.child format, which is convenient until a field name contains a dot of its own.

• Disable Dot Notation: turned on, referencing child fields as parent.child is disallowed and the name is read literally; turned off, dot notation keeps working.

Shape of the result, not content of it. This option is recommended once Fields to Split By is in use, because that is when several results exist at the same time.

• Each Split in a Separate Item: one output item per split out field.
• All Splits in a Single Item: one item that lists the split out fields.

Real batches are rarely clean. Some items simply do not carry the fields you are splitting by, and this option decides whether they still count.

• Ignore items without valid fields to group by: turned on, input items that do not contain the Fields to Split By are ignored; turned off, they are kept.