Clean up one spreadsheet or compare two, right in your browser
Upload
XLSX / CSV supported
Match columns
Pick the key and columns
Compare
Differences highlighted
Export
Excel or CSV report
Click to choose a file (.xlsx, .xls, .csv)
Choose fileOnly needed to compare two files. Skip it to tidy one file.
Choose fileSpreadsheets hold the stuff that matters at work: sales numbers, customer lists, stock counts, project trackers. But when you get "version 2" of a file and need to know what changed, Excel doesn't make it easy. You end up scrolling two windows side by side and hoping you didn't miss a row. This tool does that checking for you in a few clicks. It can also tidy up a single messy file: stray spaces, duplicate rows and inconsistent capital letters.
Everything runs in your browser with JavaScript. Your files are never uploaded to any server, so it's safe to use with customer lists, salaries or financial data.
Pick a key column such as Employee ID, email or SKU. Even if the rows are sorted differently in each file, the tool lines them up by that key and shows exactly which values changed and which rows exist in only one file.
Before this version (v3) went live, I ran 51 automated checks on the publish version of this page, in a Chromium-based browser at phone width. Last full test run: 18 October 2026.
What the checks cover: comparing two files by key (the test data has 12 rows: 6 identical, 3 changed and 3 missing, and the tool has to report exactly that), matching columns by name, the tidy-up options, comparing two columns in one file, and the language switch.
Problems found and fixed: a second review pass on 18 October found 15 problems, and all 15 were fixed before v3 went live. Files are read cell by cell, dates follow the Excel serial number so time zones cannot shift them, and CSV files are read as text so leading zeros stay.
What to keep in mind: only the first sheet is read, and the checks use small example files. Look at a few highlighted rows yourself before you send a report to someone. Found a problem? Tell me on the Contact page.
Yes. No sign-up, no limits, no watermark.
No. The files are read by your own browser. Closing the tab clears everything.
No. Rows are matched by the key column, and columns are paired by name, ignoring capital letters and spaces. If a column was renamed, pair it by hand in step 2.
Yes. Upload only File A, choose "Compare two columns" and pick the two columns. "As two lists" shows which values are missing from the other column, whatever the row order. "Row by row" checks each row. You can remove duplicates first, or keep them so a value that appears more often in one column counts as a difference.
The tool pairs rows with the same key in the order they appear and lists those keys above the results, so you can check them by hand.
Plain numbers are compared as numbers. Codes with a leading zero, such as 007, are treated as text, because the zero usually matters. CSV files are read as text, so leading zeros are kept.
The first sheet. Move the sheet you want to the front, or save it as its own file.
No fixed limit. 20,000 rows take a few seconds on a normal laptop. The results table shows the first 500 rows; the download always has every row.
The key is the column used to line up rows in both files, such as an ID or email
Columns are paired by name automatically (capital letters and spaces don't matter). If a column has a different name in File B, such as "Dept" and "Department", pick it on the right.
Only one file was uploaded, so the tool cleans it instead of comparing
For example, last month's customer emails in one column and this month's in another
Each value is looked up in the other column, like VLOOKUP. Values found in both go on the same row.
Numbers match by value (5200 = "5200.00"). Empty cells are skipped. If a value appears more than once, the row shows the first one and the result lists it for checking.
Total rows
Identical
Changed
Only in one file
Choose the file type and which rows to include