Perform Left Join or Inner Join between two sheets in an Excel workbook (or two files) on a common key column. Pro tier.
Free is enough for most one-off jobs. Pro raises the file and batch caps; Pro + Media unlocks GB-scale streaming and unlimited duration.
Larger files supported on Developer (5 GB CSV) and Enterprise (unlimited). All processing happens in your browser — files never reach a server.
Upload one or two XLSX/CSV files containing the sheets to join
Select the key column and join type (Left or Inner)
Download the merged output as a new sheet
0 bytes uploaded. Multi-Sheet Joiner runs entirely in your browser using SheetJS and ExcelJS. Your spreadsheets never leave your device.
Inner Join: only rows with matching keys in both sheets are included. Left Join: all rows from the left sheet are kept; unmatched right-sheet columns are blank.
Yes — add multiple key columns and each row is matched on the composite key (all selected columns must match).
Transform columns-as-variables (wide format) into rows-as-observations (long format). Required for Power BI, Tableau, and pandas. Pro tier.
Open toolApply custom regular expressions to any column and extract matching substrings into new columns. Pro tier. Browser-local.
Open tool