Add your MTS file
Drop one or more .mts files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
MTS to AVI
Pulling the soundtrack out of a .mts video into .avi audio keeps what you can hear and drops the picture entirely. Free, private, and validated — the file never leaves your browser.
Private for supported formats — processed in your browser
Runs on your deviceConvert supported files
Drop MTS files here
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.About converting AVCHD video to AVI video
Pulling the soundtrack out of a .mts video into .avi audio keeps what you can hear and drops the picture entirely. An .mts file is AVCHD footage as written to a camcorder's memory card, containing H.264 video inside an MPEG transport stream. Sony and Panasonic camcorders from the late 2000s onward filled SD cards with .mts clips, so the extension is familiar to anyone importing family or event video.
An .avi file is Microsoft's Audio Video Interleave container, one of the oldest video wrappers still in circulation. It stores video and audio in alternating chunks inside a RIFF structure, and the extension remains common on older camcorder captures and DivX-era rips. For this route the practical draw is simple, thoroughly reverse-engineered structure and virtually every desktop player and converter opens it — balanced against no streaming support of any kind, which is worth knowing before you commit a large batch.
Why convert MTS to AVI?
The usual reason to take .avi audio out of a .mts file is that only the sound matters — a talk, interview, song, or podcast segment. Keeping the video stream would waste storage, and a dedicated audio file is easier to trim, tag, and play. On the source side, transport-stream packet overhead makes files larger than the same video in MP4; on the target side, the payoff is simple, thoroughly reverse-engineered structure, which is exactly what you want for playing back footage digitized from DV and Hi8 tapes.
MTS vs AVI at a glance
| Aspect | AVCHD video (.mts) | AVI video (.avi) |
|---|---|---|
| Format type | Container — quality depends on the codecs and settings inside | Container — quality depends on the codecs and settings inside |
| How it stores data | uses 192-byte transport packets, standard 188-byte packets plus a 4-byte arrival timestamp, matching Blu-ray's BDAV layout | interleaves audio and video chunks inside a RIFF file, with the codec identified by a four-character FourCC code |
| Strongest at | importing camcorder footage into Premiere, Resolve, or Final Cut | playing back footage digitized from DV and Hi8 tapes |
| Weak spot | transport-stream packet overhead makes files larger than the same video in MP4 | no streaming support of any kind |
| Metadata | recording date, camera settings, and GPS coordinates on some models are stored in the AVCHD folder's clip-info files rather than in the .mts stream itself | rIFF INFO chunks store basic fields such as title, artist, and encoding software, but nothing comparable to ID3 or MP4 atoms exists |
Pick AVI as the output
Select .avi in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if AVI is selectable, the route is real and validated.
Convert on your device
Press Convert. A WebAssembly FFmpeg build demuxes the audio track and re-encodes it locally; the video stream is simply discarded.
Verify and download
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid AVI file. Outputs keep the original filename with the .avi extension.
MTS to AVI questions, answered
Will converting MTS to AVI lose quality?
Since mts is container-oriented and avi is container-oriented, the conversion preserves the source content exactly as stored; no additional compression pass is applied beyond what .avi itself requires.
Is it private to convert MTS files here?
Yes — the .mts file is processed inside your browser tab and never uploaded. A WebAssembly FFmpeg build demuxes the audio track and re-encodes it locally; the video stream is simply discarded. Close the tab and the file is gone from memory.
Where will the AVI file work?
Windows still opens .avi natively and macOS handles common variants through third-party players, though browsers never adopted the container. Whether a specific file plays depends entirely on the codec inside, so an old Indeo or Cinepak recording may need VLC even on Windows.
Will the AVI file be bigger or smaller than my MTS?
Much smaller — the video stream is usually 80–95% of a .mts file's weight, and it is discarded entirely. The remaining audio is re-encoded at the bitrate implied by your quality setting.
What happens to the metadata in my MTS file?
This converter strips container metadata deliberately (the FFmpeg command runs with metadata mapping disabled) so exported files do not leak recording details. In the source, recording date, camera settings, and GPS coordinates on some models are stored in the AVCHD folder's clip-info files rather than in the .mts stream itself; none of it is transmitted anywhere because the file never leaves your browser.
Can I convert AVI back to MTS?
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .mts → .avi → .mts is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.