Case Sensitivity Across File Systems

For software engineers, understanding file system case sensitivity is necessary for building cross-platform software. While modern file systems increasingly offer flexibility, there are still differences in the real world. You can avoid pitfalls and ensure smooth interoperability with careful development practices and awareness of the nuances of file system behavior.

Case Sensitivity and Case Preservation

• Case Sensitivity: Determines whether a file system treats file names with different capitalization as distinct. For example, file.txt and File.txt are different files in a case-sensitive system.
• Case Preservation: Indicates whether a file system retains the original capitalization of file names, even if it’s not case-sensitive.

Case Sensitivity and Preservation Across Common File Systems

The most common file systems currently in use on modern systems are NTFS (Windows), EXT (Linux), and APFS/HPS+ (macOS). For the most part, they are comparable. See the table at the bottom of the article for a breakdown of other legacy and cloud file systems.

Windows (NTFS)

• Default Behavior: NTFS is case-insensitive but case-preserving.