MKV to MP4 converter

Most MKV files store video using the H.264 or H.265 codec, both of which are natively supported by the MP4 format. When the codecs match, the converter performs a lossless remux: it copies the existing video and audio streams directly into the MP4 container without re-encoding any of the data. No quality is lost, and the process is fast. If the MKV uses a codec that MP4 doesn't support, such as VP8 or VP9, the converter re-encodes the video into a compatible codec, which takes a little longer but still produces a clean, compatible MP4 output.

The converter supports MKV files up to 2 GB, making it practical for longer recordings, high-resolution footage, and large video files. Because the video data is copied rather than rebuilt, lossless remuxing is significantly faster than re-encoding, even for large MKV files. That means you can convert a large MKV to MP4 in your browser quickly, without sacrificing quality.

MKV supports multiple audio tracks and embedded subtitle layers, while MP4 is more limited in what it can carry. The main video stream and primary audio track will convert cleanly every time. However, if your MKV includes multiple audio language tracks or embedded subtitles, those extra tracks may not carry over to the MP4 file. To avoid losing them permanently, save a copy of the original MKV before you convert.