How to use CSV Diff and Change Report
- Paste the earlier table into the before box, or choose its CSV file instead.
- Add the newer table the same way.
- Name the key column on each side and choose how keys and values are compared.
- Select Compare the versions, read the counts, then download csv-changes.csv.
Example: CSV Diff and Change Report
See what changed between two exports of the same order list.
Options
- Compare keys
- Exactly as written treats a padded key as a different key, so it looks like one row removed and another added. Ignoring spaces at the ends or letter case matches the rows and then compares their values instead.
- Compare cell values
- This setting decides what counts as a difference. It never changes what the report shows: a value that differed only by letter case still appears in full, with its real text on each side.
- When a key repeats
- A repeated key cannot be matched one to one, so the default stops and names the key rather than pairing rows at random. The other setting compares only the first row of that key and reports how many rows it left out.
- Columns on only one side
- A column present in one table and missing from the other is named in the notes and left out of the value comparison. A renamed column therefore reads as one column removed and one added rather than as a change on every row.
Supported inputs and limits
Where your input is processed
This tool processes your input in this browser. Your text and files are not uploaded to UseFreeTools. Check this tool's limits for anything it may save on your device.
A key turns a row comparison into a value comparison
Without a key, two files can only be compared line by line, and inserting one row near the top makes every later line look changed. A key such as an order number or email address lets this page find the same record in both files and report only the values that really differ.
One row per changed cell
The download holds one row for each changed cell rather than one row per record, with the key, status, column name and both values. That shape is what makes a spreadsheet filter useful: sort by column to see every price change across the file, or filter to one key to review a single record's history.
Questions about CSV Diff and Change Report
Why does an unchanged row not appear in the report?
The report lists what changed. Unchanged rows are counted in the summary so the totals add up, and leaving them out keeps the file short enough to read.
Why is my renamed column treated as a removal and an addition?
The comparison matches columns by name. A renamed column is not found on the other side, so it is reported in the notes as present on one side only, and the remaining shared columns are still compared.
What does the status column hold?
added for a key only in the newer table, removed for a key only in the earlier table, and changed when a key appears on both sides but a shared value differs. An unchanged row is counted but never listed.
Can I compare files that use different delimiters?
Not in one run. The single delimiter choice applies to both sides, so set it to the delimiter that both files use, or convert one file first.
A key repeats in both files. Why was the comparison refused?
Rows cannot be paired one to one when a key repeats, so the default stops and names the key. Choose the first-row setting to compare the first row of each key; the summary then states how many rows were left out.