Questions
How the free tool pairs and compares rows, what happens to your files, and what Calamo Pro adds.
Using the tool
What is a key column?
The column that identifies a row: a customer ID, SKU, email or invoice number. Calamo suggests one and checks that its values are unique. If no single column is unique, pick two and Calamo combines them.
Do the rows have to be in the same order?
No. Rows are paired by the key, so sorting, inserted rows and deleted rows do not matter. The files can also have different numbers of rows.
Do the columns have to be in the same order?
No. Columns are matched by name. A column that only one file has is listed and not compared.
What if a key appears twice?
Calamo flags it as a duplicate key. The first row is compared and the others are listed in the Duplicates tab with their row numbers, as in Excel.
Why are 1.50 and 1.5 not shown as a change?
They are the same number written differently. You can switch this off under “Treat as equal”, together with the rules for spaces and letter case. 1,000 is always shown as written, because it can mean a thousand or one. All the rules.
Which files can it read?
CSV and TSV, with a comma, semicolon or tab as the delimiter. The encoding is detected, including the Windows code pages Excel uses in Europe, and a title line above the header is skipped.
What do I get at the end?
Counts of added, removed, changed and unchanged rows that add up for both files, every changed cell with its old and new value, and a CSV report you can download.
Files and privacy
Are my files uploaded?
No. The page reads them with JavaScript in your browser. You can disconnect from the internet after it loads and it still works. Privacy.
How big can the files be?
A few hundred MB per file, depending on your computer’s memory. You can run the 1.2-million-row test on the home page to see how fast it is on yours.
What does the site measure?
Page views and clicks on the tool with cookie-less analytics, never file names, column names or values. See the privacy page.
Excel and Calamo Pro
Can it compare Excel files?
Not yet in the browser. Save each sheet as CSV first, or see the guide on how to compare two Excel sheets. Calamo Pro opens Excel files directly. How to compare two Excel sheets.
What does it cost?
The browser tool is free and needs no account. Calamo Pro, the desktop and command-line version, costs $49 once for one person (up to 3 computers), with a 14-day free trial.Pricing.
Can I try Calamo Pro?
Yes: download it for Windows, Linux or macOS (beta) and everything works for 14 days, with no account.
What if Calamo Pro doesn’t work for me?
Within 30 days of buying you get a full refund, no reason needed. Refund terms