Compare existing Google Sheets rows and incoming n8n records

Paste two CSV tables or JSON arrays, including their headers. Up to 2 MB per input. This diagnostic never edits a Sheet.

Existing Google Sheets rows

Existing input formatChoose local file

Incoming n8n items

Incoming input formatChoose local file

Match column in Sheet

Incoming match field

Normalize comparison key as

Diagnosis overview

Row-by-row findings

New helper column localcsv_match_key is generated on BOTH exports. Import it as Plain text, resolve empty or duplicate keys, then choose that field as Column to match on in n8n. Back up the original Sheet first; this tool never edits it.

Runs locally, without Google account access. No automatic Sheet edits or ad clicks.