Organizing files by format involves grouping digital files primarily by their type, determined by their file extension (e.g., .docx for Word documents, .jpg for images, .pdf for PDFs). Unlike organizing by project, date, or creator, this system prioritizes the technical nature of the file itself. This approach enables quicker identification based on the application required to open it, such as grouping spreadsheets separately from video clips or text documents.

For example, a photographer might place RAW files in a "NEF" folder and final edited JPEGs in a "JPG" folder within their photos directory. Similarly, a software developer could keep source code files (.py, .js) in one folder and documentation or reports (.md, .pdf) in another. Operating systems like Windows, macOS, and Linux often default to sorting by file type, and file explorer applications support this view.

Organizing by format significantly improves navigation efficiency and simplifies tasks like bulk conversions, backups, or searches for specific file types. However, it can scatter related project files across multiple type-based folders, requiring additional drilling down to find all elements of a single project. While AI-enhanced tools may offer future refinement, grouping primarily by format remains optimal for managing large archives where file type dictates handling or usage priority.