2024-12-04 00:00:00 AI file extension is associated as "Illustrator" by Adobe Systems Inc. Since Ai file is in vector format, it can be enlarged without loosing quality of the image. Instead of using bitmap image data, Ai file format is composed of paths connected by points. Ai Viewer is free app that supports .ai graphic files, display preview images. AI Viewer supports resizing of AI image, enlarge or reduce, without losing any quality. Some of the options provided in Ai Viewer are: