Convert ASF to MP4 — Free Online Converter

MP4 (MPEG-4 Part 14) is the universal video standard, playable on virtually every device, browser, and operating system in existence. ASF (Advanced Systems Format) is Microsoft's proprietary streaming container that relies on Windows Media codecs with limited cross-platform support. Converting ASF to MP4 replaces the Microsoft-specific container and codecs with the globally standardized H.264 video and AAC audio, making the content accessible everywhere.

ASF files are a relic of the Windows Media era. They require Windows Media Player or VLC for playback and are unsupported by macOS, iOS, most Android devices, web browsers, and social media platforms. MP4 with H.264 is supported by every major platform natively — no plugins, no third-party apps. If you have ASF files, converting to MP4 is the single most impactful compatibility upgrade you can make.