Did the file come back unaltered?

You sent a spreadsheet out and got one back. Put them side by side and see every cell that is not the same as when it left.

What this catches

  • Rows that were added while the file was out
  • Rows that were quietly removed
  • Individual cells that were edited, old value beside new
  • Duplicated records introduced by a merge

You will be asked which column identifies a row. Whichever column is the record’s reference or ID.

File A · original

Drop a CSV or XLSX file here, or click to browse

File B · updated

Drop a CSV or XLSX file here, or click to browse

All file data is read entirely within this browser tab. Nothing is uploaded to any server. Closing this tab discards all loaded data.

How it works

  1. Keep the copy of the file as you sent it.
  2. Load the original on the left and the returned file on the right.
  3. Pick the column that identifies a record — a reference, code or ID.
  4. Anything that is not in the matched count was changed, added or removed while the file was out.

Questions

How do I check whether a spreadsheet was modified?
Load the version you sent and the version you received, then pick the column that identifies a row. Every row is sorted into matched, changed, added, removed or duplicate, and each changed cell is shown with its previous value.
Does this verify the file itself, like a checksum?
No. A checksum tells you that something changed; this tells you what changed. It compares the data row by row and cell by cell, which is what you need when the file was legitimately edited and you want to see the edits.
What if rows were re-ordered?
Row order does not matter. Records are matched on the column you choose as the identifier, so a re-sorted file still matches cleanly.
Is my file uploaded anywhere?
No. Both files are read and compared inside this browser tab. Nothing is sent to a server, there is no account, and closing the tab discards everything.
What file formats does it accept?
CSV and XLSX. Both sides can be different formats — a CSV against an XLSX works.
How large a file can it handle?
It has been measured on 100,000 rows a side. Large files take a few seconds to parse, and the comparison itself runs in well under a second.
Can I export the differences?
Yes. The result can be exported as CSV or XLSX, so you can attach it or keep it with the period’s paperwork.