Merge multiple Excel or CSV files and compare two files

Merge Excel and CSV files

This page combines spreadsheets in the browser. Add several CSV or Excel files, line up columns by header name, and download one table. Mixed CSV and Excel files work when each file can be read as a table.

Combine multiple CSV files

Drop several CSV files in the order you want. Columns with the same header stack into one field. Extra headers from later files are added, and missing cells stay empty.

Merge Excel workbooks

Each workbook can use a different sheet. Sales from one file and Inventory from another become one table without uploading the files.

Match columns by header

Name and Email in a different order still merge. Turn on identical columns if you need every file to use the same headers before combining.

Track source files

Add a source filename column, and a source sheet column for Excel, so you can see which file each row came from after the merge.

Compare Excel and CSV files

Compare an original file with an updated file. Match by row position or by a key such as ID, email, or SKU, then review added, removed, changed, and unchanged rows.

Compare files by key column

A key is the field that identifies the same record in both files, such as employee number. Two keys, for example country plus ID, can be used when one column is not unique.

Find added and removed rows

Keys that appear only in the updated file are added. Keys that appear only in the original file are removed, even if the row order changed.

Find changed rows and cells

When the key matches but another compared column changed, the row is marked changed and the old and new cell values are listed. Skip columns such as timestamps if those edits should not count.

Export differences

Download only the differences, or an Excel workbook with Summary, Added, Removed, and Changed sheets. Unchanged rows can be included if you need a full picture.

Privacy

Reading, merging, and comparing run in your browser. NEXNARA does not upload the spreadsheets.