A .sav file is the primary proprietary file format used by SPSS (Statistical Package for the Social Sciences) software to store data. It saves datasets containing variables, their values, labels, and metadata like missing value definitions, unlike simpler formats such as .csv which only store raw data values without this contextual information. To view or edit a .sav file, you typically need specialized statistical software capable of reading this format.

SPSS itself (now IBM SPSS Statistics) is the primary application used to open and work with .sav files. Researchers, analysts, and students often use it within academic institutions, market research firms, and healthcare organizations. Alternatively, free software like PSPP provides basic .sav file viewing capabilities, while libraries for programming languages like Python (e.g., pyreadstat, pandas) allow reading .sav data into code environments.

The main advantage of the .sav format is its reliable preservation of complex metadata, ensuring analytical work is reproducible. However, its proprietary nature is a key limitation, requiring specific commercial software or adapting free tools for access, potentially creating vendor lock-in and accessibility barriers. Open formats are increasingly favored for better long-term usability and data sharing flexibility.