How do I create a readable diff of two spreadsheets using git diff?

Quick and easy with no external tools, works well as long as the two sheets you are comparing are similar:

• Create a third spreadsheet
• Type =if(Sheet1!A1 <> Sheet2!A1, "X", "") in the top left cell (or equivalent: click on the actual cells to automatically have the references inserted into the formula)
• Ctrl+C (copy), Ctrl+A (select all), Ctrl+V (paste) to fill the sheet.

If the sheets are similar, this spreadsheet will be empty except for a few cells with X in them, highlighting the differences. Unzoom to 40% to quickly see what is different.

I've done a lot of comparing of Excel workbooks in the past. My technique works very well for workbooks with many worksheets, but it only compares cell contents, not cell formatting, macros, etc. Also, there's some coding involved but it's well worth it if you have to compare a lot of large files repeatedly. Here's how it works:

A) Write a simple dump program that steps through all worksheets and saves all data to tab-separated files. Create one file per worksheet (use the worksheet name as the filename, e.g. "MyWorksheet.tsv"), and create a new folder for these files each time you run the program. Name the folder after the excel filename and add a timestamp, e.g. "20080922-065412-MyExcelFile". I did this in Java using a library called JExcelAPI. It's really quite easy.

B) Add a Windows shell extension to run your new Java program from step A when right-clicking on an Excel file. This makes it very easy to run this program. You need to Google how to do this, but it's as easy as writing a *.reg file.

C) Get BeyondCompare. It has a very cool feature to compare delimited data by showing it in a nice table, see screenshot.

D) You're now ready to compare Excel files with ease. Right-click on Excel file 1 and run your dump program. It will create a folder with one file per worksheet. Right-click on Excel file 2 and run your dump program. It will create a second folder with one file per worksheet. Now use BeyondCompare (BC) to compare the folders. Each file represents a worksheet, so if there are differences in a worksheet BC will show this and you can drill down and do a file comparison. BC will show the comparison in a nice table layout, and you can hide rows and columns you're not interested in.

Hmmm. From the Excel menu choose Window -> Compare side by side?

Do you use TortoiseSVN for doing your commits and updates in subversion? It has a diff tool, however comparing Excel files is still not really user friendly. In my environment (Win XP, Office 2007), it opens up two excel files for side by side comparison.

Right click document > Tortoise SVN > Show Log > select revision > right click for "Compare with working copy".

There is a library daff (short for data diff) which helps in comparing tables, producing a summary of their diffs, and using such a summary as a patch file.

It is written in Haxe, so it can be compiled in major languages.

I have made an Excel Diff Tool in Javascript with help of this library. It works well with numbers & small strings but the output is not ideal for long strings (e.g. a long sentence with with minor character change).

I would use the SYLK file format if performing diffs is important. It is a text-based format, which should make the comparisons easier and more compact than a binary format. It is compatible with Excel, Gnumeric, and OpenOffice.org as well, so all three tools should be able to work well together. SYLK Wikipedia Article

I found an openoffice macro here that will invoke openoffice's compare documents function on two files. Unfortunately, openoffice's spreadsheet compare seems a little flaky; I just had the 'Reject All' button insert a superfluous column in my document.

I'm the co-author of a free, open-source Git extension:

https://github.com/ZoomerAnalytics/git-xltrail

It makes Git work with any Excel workbook file format without any workarounds.

Diff Doc may be what you're looking for.

• Compare documents of MS Word (DOC, DOCX etc), Excel, PDF, Rich Text (RTF), Text, HTML, XML, PowerPoint, or Wordperfect and retain formatting
• Choose any portion of any document (file) and compare it against any portion of the same or different document (file).

I don't know of any tools, but there are two roll-your-own solutions that come to mind, both require Excel:

1. You could write some VBA code that steps through each Worksheet, Row, Column and Cell of the two Workbooks, reporting differences.

2. If you use Excel 2007, you could save the Workbooks as Open-XML (*.xlsx) format, extract the XML and diff that. The Open-XML file is essentially just a .zip file of .xml files and manifests.

You'll end up with a lot of "noise" in either case if your spreadsheets aren't structurally "close" to begin with.