What is the difference between mkv and mp4 files?

MKV (Matroska Video) and MP4 (MPEG-4 Part 14) are both container formats used for storing audio, video, and other multimedia content. While they have similarities, there are some key differences between the two:

1. Container Structure: MKV is a flexible container format that can hold an unlimited number of audio, video, subtitle, and metadata tracks within a single file. It is known for its support of various codecs and advanced features like chapter navigation and multiple audio streams. On the other hand, MP4 is a more standardized container format that follows strict rules for organizing audio and video data. MP4 typically has a simpler structure and is widely supported across devices and platforms.
2. Video and Audio Codecs: Both MKV and MP4 support a wide range of video and audio codecs, allowing for high-quality multimedia content. However, MKV has more flexibility in terms of codec compatibility, as it can handle virtually any codec available. MP4, on the other hand, has a more limited range of officially supported codecs, although it still covers the most commonly used ones like H.264 (AVC) and AAC.
3. Subtitle and Metadata Support: MKV has robust support for subtitles and metadata, offering more options for including multiple subtitle tracks, different subtitle formats, and extensive metadata information. MP4 also supports subtitles and metadata, but it may have some limitations compared to MKV in terms of subtitle formats and the number of subtitle tracks.
4. Device and Platform Compatibility: MP4 is widely supported by various devices, operating systems, and media players, making it a popular choice for compatibility across different platforms. MKV support, while improving over the years, may not be as universal as MP4. Some older or less common devices or media players may have limited or no support for MKV files, requiring additional software or conversion.
5. File Size and Compression: Both MKV and MP4 can achieve similar levels of video and audio compression using various codecs. However, due to its more flexible nature, MKV files may be slightly larger in size compared to MP4 files with the same content and quality. The difference in file size is generally minimal and may vary depending on the specific codecs and settings used during the encoding process.

In summary, MKV offers greater flexibility, advanced features, and extensive codec support, making it a preferred choice for those seeking more customization options or working with specific codecs. MP4, on the other hand, provides better compatibility across devices and platforms, making it a widely accepted format for multimedia content distribution. The choice between MKV and MP4 depends on factors such as intended usage, device compatibility, codec requirements, and desired features.