Rows are paired by key columns such as a customer or product code (or a combination of columns), so a different row order doesn’t matter. Row-order comparison is available too.
CSV DiffFind what changed between
Find what changed between
two CSVs, without guessing.
Compare an old and a new CSV: added, removed and changed rows, with “before → after” for every changed cell. Rows whose key appears more than once can’t be matched for sure, so they are listed instead of being paired arbitrarily.
No uploadValues are never changedNo ambiguous matching
A: original (old file)Drop it here or clickChoose a file
B: compared (new file)Drop it here or clickChoose a file
Compares two versions (September and October) of a fictional customer list.
Keys that appear on several rows and rows with an empty key are not matched by guesswork; they are listed for review. Added, removed and reordered columns are shown as well.
Save a change list with one line per changed cell, added or removed row, and a summary report. Values are written exactly as they are in your files.
How to use it
- Choose the old file as A and the new file as B.
- Choose how rows are paired. If each row has a unique column such as a customer code, “Match by key columns” is recommended.
- If needed, ignore differences in surrounding spaces, letter case or full-width forms.
- Review the changes and save the change list or the report.
FAQ
Can I compare files whose rows are in a different order?
Yes, with “Match by key columns”: rows are paired by their key values, so order doesn’t matter. “Compare by row order” walks both files from the top and finds inserted and deleted rows.
What happens when a key appears on two rows?
There is no way to know which rows belong together, so they are not matched. The key and row numbers are listed for review. Adding another key column often makes the key unique.
Can differences in spaces or full-width characters be ignored?
Yes: surrounding spaces, letter case, and full-width/half-width and other compatibility forms (NFKC). These settings only affect the comparison; the values shown and saved are the original ones.
How large can the files be?
Up to 10 MB per file; the comparison runs in a Web Worker in your browser. The change list can be saved up to 300,000 lines. If a row-order comparison finds too many differences, it switches to comparing rows by position and tells you.