MP4 is a video format: it packages H.264 or H.265 video with AAC audio in a container format widely supported across every platform and device. ICO is a image format that bundles multiple raster images at different resolutions (16x16 through 256x256) into a single file for use as application icons. This conversion changes the file's encoding, compression method, and supported feature set. Metadata such as creation date and embedded colour profiles is preserved where the target format supports it. Converting between these two formats is common when the source application does not support ICO natively or when the target platform only accepts ICO. 1converter processes this conversion server-side using open-source tools. Files are transferred over HTTPS, converted on secure cloud servers, and automatically deleted after 24 hours.