Hogandiff compares two Excel files and shows you what changed, cell by cell.
It is built for the kind of spreadsheet that is used as a document rather than a database: dense grids, merged headers, layouts that shift when someone inserts a row — or a column.
That last part is where most approaches break down. Exporting to CSV and running a text diff, or lining the two sheets up cell by cell, treats the row as the unit of comparison: insert one column and every field on the line moves, so entire rows come back marked as changed. Hogandiff treats rows and columns as two equal axes and works out both correspondences at the same time, so an insertion, deletion or move on either axis is absorbed instead of smeared across the result. What you get back is the handful of cells that actually changed.
Neither axis needs a key — no key column, no key row. When Hogandiff's guess is not what you meant, you can weight or pin individual rows and columns by hand.
The result is not a report you have to learn to read. You get back copies of both workbooks with the changed cells colored in, plus a separate report workbook listing the differences sheet by sheet, so you review them in Excel like any other file.
It compares cell values or formulas (your choice), cell comments, and the text inside shapes, text boxes and SmartArt. It reads .xlsx, .xlsm and legacy .xls, including comparing one format against another, and it can compare two worksheets, two workbooks, or two folders recursively. Password-protected workbooks can be compared from the desktop app and through the MCP server, though not from the command line.
The same engine comes in three shapes: a desktop app, a command-line tool that reports the outcome as an exit code for scripts and Git difftool setups, and an MCP server so that AI assistants can run the comparison and talk you through what changed.
Free for personal and commercial use. No installer and no runtime to install: unzip the folder and run it. Microsoft Excel is not needed to run a comparison. Everything happens on your own machine; the contents of your files are never sent anywhere. The application runs in English, Japanese or Chinese, though its documentation and license agreement are in Japanese only.
Formatting is deliberately not compared (fonts, fill colors, borders, number formats, the appearance of objects, charts and macros), with one exception: strikethrough is detected. The .xlsb format and non-worksheet sheets are not supported.
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