First-track mapping
The converter uses `0:a:0`; it does not yet choose between languages, commentary, or alternate mixes.
Convert MKV to MP3 online at 128, 192, or 320 kbps. Trim the clip, keep the MKV private, and download the first audio track free in your browser.
Your video stays on this device. Processing starts only after you click Convert.
MKV to MP3
Convert one MKV audio stream while making the multi-track and codec limits visible.
The converter uses `0:a:0`; it does not yet choose between languages, commentary, or alternate mixes.
MKV can contain AAC, Opus, Vorbis, AC-3, and more, so container support alone cannot guarantee decoding.
Video, subtitles, chapters, and attachments are excluded from the MP3.
Track-aware workflow
Treat the finished result as unverified until the selected track has been heard.
Browser memory makes native desktop tools more appropriate for very large Matroska files.
Select the useful time range and use 128, 192, or 320 kbps according to the content.
Listen to the result because the first audio stream may be commentary or a different language.
Local extraction boundary
Demuxing, decoding, and MP3 encoding run inside the current browser session.
Clear answers about languages, codecs, subtitles, size, and Original mode.
The current release converts the first audio stream, identified by FFmpeg as `0:a:0`. There is no language selector yet.
The MP3 will contain that commentary. Use a track-aware desktop tool when another language or mix must be selected.
No. MP3 is audio-only, so subtitles, video, chapters, and Matroska attachments are not copied.
MKV accepts many codecs, but success depends on whether the specific decoder is available and the stream is valid.
No. Video resolution is unrelated to the encoded audio stream and is discarded during conversion.
MP3 mode decodes and re-encodes the first track. Original mode copies its encoded packets to MKA without a new audio encode.
Related tools and guides
Use a related converter or guide when you need another format, a smaller file, or no re-encoding.
Use the general video-to-MP3 workflow for another supported video container.
Open the video to MP3 converterCopy the first encoded audio stream to MKA when you need to avoid a new MP3 encode.
Explore original audio extractionConvert an MP4 source to a compact MP3 using the same browser-local workflow.
Open the MP4 to MP3 converterChoose an output format by balancing file size, audio quality, and editing needs.
Read the format comparison