MTS to MP4 converter

Sony and Panasonic AVCHD camcorders record MTS/M2TS files that many editors and phones will not import.

Drop a MTS file hereThe converter loads in your browser.

What happens to your MTS

AVCHD is H.264 video with AC-3 audio in a transport stream. The video is copied into MP4 and the AC-3 audio converted to AAC, so it is fast and the picture is untouched.

Tip: AVCHD 1080i footage is interlaced. Tick "Deinterlace" if you see comb lines (this forces a video re-encode).

How to convert MTS to MP4

  1. Drop your MTS file on the box above, or tap it to pick one. The engine (about 31 MB) loads once per visit.
  2. The converter reads the file's streams and shows which codecs are inside.
  3. Keep the defaults, or pick a quality and resolution.
  4. Press the button, wait for the progress bar, then download your MP4.

Prefer the command line?

This is the FFmpeg command the converter runs for a typical MTS (h264 + ac3). Paste it into a terminal with FFmpeg installed for batch jobs or files too big for a browser tab:

ffmpeg -y -i input.mts -map 0:v:0 -map "0:a:0?" -sn -dn -c:v copy -c:a aac -b:a 160k -movflags +faststart output.mp4

Video is copied; only audio is re-encoded. Your own file may contain different codecs; the converter above detects them and adapts. For other jobs, ask the FFmpeg command helper.

Questions

Does MTS to MP4 lose quality?

The video stream is copied, so no. Only the audio is re-encoded from AC-3 to AAC.

Is my MTS file uploaded?

No. The MTS is read from your device by FFmpeg running as WebAssembly in the page, and the MP4 is written back to your device. No server ever receives it.

Is there a size limit for MTS to MP4?

We set none. The practical limit is browser memory: roughly 2 GB of output on a computer, and much less on phones.