Compare Two CSV or Excel Files: Find Added, Removed and Changed Rows
Find out exactly what changed between two versions of a file, row by row and cell by cell.
After a data migration, an export or a system update, you need to know what changed. Looking at two large files side by side is not practical.
Data Comparison matches the rows in both files using a key column, such as an id. It suggests a key for you, and you can click Use first column as key, pick one or more columns, or type the column names yourself. If you choose no key, it uses the first two columns of the files as the key. It then lists the rows that were added, removed or changed, and shows which cells are different.
Data Comparison works with CSV and Excel (.xlsx) files, and the two files can be different types. JSON and Parquet files are not supported, so convert them to CSV first with the Format Converter. Both files stay in your browser. Because two files are held in memory, it works best with files under about 50 MB.
How to use the Data Comparison: step by step
- Open Data Comparison.
- Load the "before" file and the "after" file (CSV or Excel).
- Choose the key: click Use first column as key, pick columns, or type names such as id or id, region. With no choice, the first two columns are used.
- Review the added, removed and changed rows.
When to use the Data Comparison
- Checking a data migration
- Finding what changed between two exports
- Testing a report after a code change
- Reviewing edits made by a colleague
Tip: Pick a key that is unique in both files. If one column repeats, add a second one, such as id and region. The column names must match in both files.