Figuring out how a document has changed from one version to another isn’t always the simplest task. It’s further complicated when that document is longer or more complex, like source code.
The tools collected here can help you analyze and compare your documents and files, as well as merge them if necessary. There are tools to compare everything from Word docs to WAV files, and everything in between (including plenty that support syntax highlighting for code). Some are free and some are paid, and there are options available for Mac OS X, Windows, and Linux.
File and Document Comparison Tools
Beyond Compare lets you easily compare files and folders, including text files (with syntax highlighting for HTML), Word Docs, and PDF files, among others. Available for Windows and Linux for $30 (standard edition) to $50 (pro edition).
Kaleidoscope lets you compare text documents (including source code) and images. It has built-in integration with other programs, and can read .psd, .txt, .png, .jpg, and .html files. Available for Mac OS X for €29.
Workshare Compare is an enterprise-level document comparison tool that lets you compare Word documents and text-based PDFs. You can compare one document to multiple others. It’s available for Windows for $145 for a one-year subscription. There’s also a Basic version for $99/year that only compares Word documents.
Doc-Proof works to compare XML, Word, text, and PDF files. It makes it possible to quickly compare fonts, sizes, deletions, insertions, spelling, and location.
ExamDiff is a freeware visual file comparison tool for Windows. It includes automatic change detection, one-click recompare, drag and drop support, and is fully customizable. There’s also a Pro version with more features for $34.99.
Diff Doc can be used to compare Word, Excel, PowerPoint, PDF, RTF, text, HTML, XML, and other document types. It’s available for Windows.
Compare Suite lets you compare by keyword, compare two folders, ignore certain words, and includes syntax highlighting to make it easier to compare code documents. Compare Suite is available for Windows for $70 for a single user license.
WinMerge is an open source differencing and merging tool for Windows. It shows comparisons visually and makes it easy to merge documents.
Araxis Merge is a three-way document comparison, merging, and folder synchronization tool. It can be used to compare source code, web pages, XML, and other text files, as well as Word and Excel documents, PDFs, and RTF files. It’s available for both Windows and Mac OS X for $129 for the Standard version and $269 for the Professional version.
Changes lets you sync folders, compare both code and prose, and even compare right inside a variety of text and code editors (including Coda and TextWrangler). Changes are available for Mac OS X for $49.95 for a single license.
CodeCompare is a source code comparison tool built on the .NET framework that includes support for syntax highlighting, Visual Studio integration, three-way merge, version control integration, and folder synchronization. Basic functionality is free, but there’s also a Pro version for $49.95.
Compare++ has built-in analysis functions for C/C++, C#, Java, CSS3 and more. It’s available for Windows for $29.95 for a single user.
DiffMerge is a free document comparison and merging tool for Windows, Mac OS X, and Linux. It includes full editing support for compared files, and merging for up to three files.
Kompare is a graphical difference viewer that lets you compare two text files It’s included in the KDE Software Development Kit.
UltraCompare is a file and folder compare utility that works for text files, Word documents, zip files, and jar archives. In addition to local/network directory compare, it also supports FTP compare. It’s available for Windows for $49.95.
This is a free, bare-bones, web-based comparison tool. Just enter the master text and the second text and choose whether you want it compared inline or side-by-side.
Diffuse is a free Python text comparison and merge tool for Windows and Linux.
Compare & Merge is a file comparison and merging utility for source code, HTML, XML, and other text-based files. It’s available for Windows for $39.95.
Active File Compare has syntax highlighting support for C++, C#, Java, Visual Basic, HTML, PHP, XML, and many other programming languages. It can also compare files that exist in Zip, Tar, and GZip archives. It’s available for Windows for $15.95 for a business license or $9.95 for a personal license.
Colored Diffs is a Thunderbird plugin for highlighting differences in CVS or SVN email notifications about changes made by other users.
Compare It! lets you compare not only text files, but also binary and image files, and includes an editing engine. It’s available for Windows for $29.
Compare PDF has support for both PDF and text file comparisons. It can be integrated with other software products. Compare PDF is available for Windows for $35 for a single user license.
DiffPDF is a free program that lets you compare two PDF files, with both text and appearance views (to check things like reformatting of a paragraph or if an image is changed). There are versions for Windows, Mac OS X and Linux.
Meld is a free visual comparison and merging tool for Linux. It allows for comparison of two or three documents, and in-place edits. It also allows folder comparisons.
Files Compare Tool is a visual comparison app for files and directories. It offers color-coded side-by-side comparison and a powerful editing engine.
Quick Diff is a simple, free online comparison tool. Just copy and paste the two bits of text you want to compare, and indicate whether you want it to compare side-by-side or inline.
FourierRocks is a graphical WAV file comparison tool. It’s open source, and works on the .NET framework.
The tools above can be a great way to compare documents and files. But don’t overlook the document comparison tools built into many programs developers and designers already use. Dreamweaver has built-in tools for comparing documents. So does Google Docs. Even WordPress has comparison tools for posts and pages. Leave us a comment and tell us what your favorite comparison tools are?