Changes to MKV format support in Premiere Pro and Adobe Media Encoder
Video editing workflows.
Our previous MKV file format was limited to decoding for playback. We have never offered support for encoding MKV, and overall usage of this format has been very low.
Users who need access to MKV files can consider third-party utilities. For rendering out video content for online platforms we encourage our users to take advantage of existing output options, such as H.264 and HEVC formats, which are widely used and supported.
See the full list of supported formats: