Files with the .ARW extension contain digital images in raw and uncompressed form – exactly as captured by the camera CCD sensor. The format is based on the TIFF specification, although it is not standardized – the encoding can be different depending on the camera model. ARW files are unique to Sony digital cameras. To ensure that it can handle the right ARW files, the program used for opening said files must support the relevant camera model.

Using a raw ARW file allows for non-lossy editing and exporting into popular raster image files, such as JPG or TIFF, for the purposes of sharing or printing.