How to Compare Binary Files in Windows

Comparing files is a common task, especially when troubleshooting software issues or ensuring data integrity. While comparing text files is straightforward, comparing binary files requires specialized tools. This article explores various methods for comparing binary files in Windows, ranging from built-in utilities to third-party solutions.

Using Windiff.exe for Visual Comparison

Windows includes a built-in utility called Windiff.exe, designed for visual comparison of files and folders. While primarily used for text files, it can also highlight differences in binary files. Windiff.exe presents a side-by-side view, clearly marking discrepancies in content. To use Windiff.exe:

Locate Windiff.exe: It’s typically found in the SupportTools folder on the Windows installation media or within the Support.cab file included with service packs.
Launch Windiff.exe.
Choose “Compare Files” or “Compare Directories” from the File menu, depending on your needs.
Select the two binary files or folders you wish to compare. Windiff will analyze the content and display the results. Differences will be highlighted, allowing you to visually identify variations.

While Windiff provides a visual representation, it doesn’t offer detailed byte-level comparison for binary files. It’s most effective for quickly identifying if two binary files are different, rather than pinpointing the exact differences.

Command-Line Tools: FC.exe and COMP.exe

For more granular control and scripting capabilities, Windows offers command-line utilities:

FC.exe (File Compare): This tool compares files line by line. For binary comparison, use the /b switch: fc /b file1.bin file2.bin. This command will indicate whether the files are identical or display the differing bytes.

COMP.exe (Compare): This utility compares files byte by byte and can also compare entire folders. The command comp file1.bin file2.bin provides a detailed comparison. You can customize the comparison with various switches. For instance, to compare files regardless of case, use: comp file1.bin file2.bin /i.

Leveraging Third-Party Tools for Binary File Comparison

Numerous third-party tools offer advanced features for binary file comparison:

Hex Editors: These tools display the raw hexadecimal representation of files, allowing for precise byte-level examination and comparison. Popular hex editors include HxD, WinHex, and 010 Editor.
Beyond Compare: This comprehensive file and folder comparison tool supports binary comparison, highlighting differences and offering features like synchronization and merging.
Total Commander: A powerful file manager with built-in binary comparison capabilities.

Verifying File Integrity with Checksums

Checksums (e.g., MD5, SHA-1, SHA-256) provide a unique fingerprint for a file. Comparing checksums is a reliable way to verify if two files are identical, even if their names or timestamps differ. Numerous tools are available to generate and compare checksums, such as:

Certutil: A built-in Windows command-line tool that can calculate various checksums (e.g., certutil -hashfile file.bin MD5).
HashTab: A Windows shell extension that adds a checksum tab to file properties, enabling easy checksum generation and comparison.

Conclusion

Choosing the right method for comparing binary files in Windows depends on your specific needs. Windiff offers a quick visual overview, while command-line tools provide greater flexibility. Third-party tools and checksum comparison offer advanced features for in-depth analysis and verification. By understanding these options, you can effectively compare binary files for troubleshooting, data integrity checks, and other essential tasks.