Select or Medium (360p) . While not exactly 240x320, 360p is usually the closest compatible standard for modern feature phones. Tips for Success
Most modern downloaders default to 720p or 1080p, so you need tools that let you manually select lower resolutions: Youtube video downloader 240x320
: Many older Nokia, Samsung, and Sony Ericsson "dumbphones" natively support 3GP or MP4 files at exactly this resolution. Select or Medium (360p)