Guides

Short, practical guides for comparing Excel and CSV files using the columns that identify each row, reconciling exports, and finding duplicate rows — all aligned with how Columnics works in your browser.

How to compare two Excel or CSV files by key columns
Use composite keys (order id, SKU + date, etc.) to match rows between two spreadsheets, see only-in-A / only-in-B / changed rows, and export — privately in your browser with Columnics.
Reconcile two spreadsheet exports (accounting, vendors, ERP)
Reconcile two Excel or CSV exports from your bank, vendor, or ERP: align on transaction or document ids, spot missing rows, and highlight field-level differences before close — with Columnics in the browser.
Find duplicate rows in Excel or CSV by selected keys
Detect duplicate keys in a single spreadsheet: choose the columns that define uniqueness, list duplicate vs unique rows, and export — without uploading your file with Columnics.