MKV containers often hold H.264 video and multiple audio tracks — perfect for archiving, problematic for phones. HandBrake can remux without re-encoding or transcode for tough codecs.
Inspect the source
Open the MKV in HandBrake and note the video codec on the Summary tab. If it is already H.264, you may only need to change the container to MP4. Play the file in VLC first to confirm audio tracks and subtitle types — map them using the subtitles guide before batching via batch encoding.
Fast remux path
When HandBrake offers passthrough for video, select H.264 copy, choose MP4 format, pick audio tracks to keep, disable unnecessary subtitles, then start — this completes in minutes without generation loss. Similar logic applies to Apple MOV in the MOV to MP4 guide.
When re-encoding is required
HEVC, VP9 or DTS audio inside MKV may require transcoding for older TVs. Use H.264 video and AAC audio for maximum compatibility, with RF from the best settings guide. Codec theory lives in H.264 vs H.265 vs AV1; choose H.265 only when players support it.
Size and quality tuning
If outputs are still huge, apply file size reduction strategies — resolution, audio and RF — without skipping verification. Hardware encoders from the hardware acceleration article accelerate long re-encode jobs from screen recordings originally captured in OBS — see the OBS review.
Verify output
Test on the weakest device in your chain. Compare against FFmpeg remux commands in HandBrake vs FFmpeg if you need scripted repeats. YouTube uploads should align with YouTube export settings after conversion.
Multi-track and foreign film workflows
Foreign films with multiple audio languages need explicit track selection — default HandBrake behavior may keep only the first track. Document which language maps to which player for client deliverables. Commentary tracks inflate size; disable them for airline or streaming cuts while retaining them in archival MKV masters stored separately from HandBrake MP4 derivatives.
Disclosure: ReviewForge is an independent editorial website. We are not affiliated with HandBrake or other software vendors reviewed here. Pages may display advertising from Google AdSense. See our editorial policy and disclaimer.