In n8n, items coming from multiple input connections into a Filter node are merged into a single stream, so you lose information about which input they came from.

To count items per input, you need to tag them before the Filter. Add a Set (or Function) node on each input path and add a field like source: "inputA" / source: "inputB".

After the Filter node, you can count items by grouping on that field (using a Function node or other aggregation logic).

If you don’t want inputs to merge at all, keep the Filter and counting logic in separate branches or workflows.

n8n doesn’t provide a built-in “count per input connection” feature, so tagging items before merging is the usual workaround.