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 MP4
Converting .mts video to .mp4 means re-encoding the picture and sound into a different container and codec family, and this page does it entirely in your browser. 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 MP4 video
Converting .mts video to .mp4 means re-encoding the picture and sound into a different container and codec family, and this page does it entirely in your browser. 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 .mp4 file is a multimedia container that bundles compressed video, audio, subtitles, and chapter data into a single stream-friendly package. It is the default delivery format for nearly every phone, camera, and video platform, which makes .mp4 the safest target when a clip has to play everywhere. For this route the practical draw is plays natively in every modern browser, operating system, and mobile device and streams efficiently once faststart or fragmentation is applied — balanced against fewer track, attachment, and chapter features than Matroska, which is worth knowing before you commit a large batch.
Why convert MTS to MP4?
The practical trigger for this conversion is usually a mismatch: with .mts, transport-stream packet overhead makes files larger than the same video in MP4. Switching to .mp4 buys you plays natively in every modern browser, operating system, and mobile device, which is why it is the better fit for publishing video to the web, social media, or a client who has not specified a format. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
MTS vs MP4 at a glance
| Aspect | AVCHD video (.mts) | MP4 video (.mp4) |
|---|---|---|
| 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 | typically carries H.264/AVC or H.265/HEVC video with AAC audio, though the box structure also accepts AV1, MP3, and timed-text tracks |
| Strongest at | importing camcorder footage into Premiere, Resolve, or Final Cut | publishing video to the web, social media, or a client who has not specified a format |
| Weak spot | transport-stream packet overhead makes files larger than the same video in MP4 | fewer track, attachment, and chapter features than Matroska |
| 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 | iTunes-style metadata atoms (title, artist, cover art) plus XMP and per-track language tags; ID3 is not native to the container |
Pick MP4 as the output
Select .mp4 in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if MP4 is selectable, the route is real and validated.
Convert on your device
Press Convert. The conversion runs on an FFmpeg engine compiled to WebAssembly, executing entirely inside your browser tab.
Verify and download
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid MP4 file. Outputs keep the original filename with the .mp4 extension.
MTS to MP4 questions, answered
Will converting MTS to MP4 lose quality?
Both sides are re-encoded, so expect a small generation loss controlled by the quality setting: mts is container-oriented and mp4 is container-oriented. For visually or audibly transparent results keep quality high; for smaller files lower it and compare.
Is it private to convert MTS files here?
Yes — the .mts file is processed inside your browser tab and never uploaded. The conversion runs on an FFmpeg engine compiled to WebAssembly, executing entirely inside your browser tab. Close the tab and the file is gone from memory.
Where will the MP4 file work?
Every current browser, including Chrome, Firefox, Safari, and Edge, plays H.264 .mp4 files without plugins, and hardware decoding is ubiquitous on phones and televisions. Files using HEVC inside the container are the main exception: Apple devices handle them well, while Firefox depends on the operating system's decoder.
Will the MP4 file be bigger or smaller than my MTS?
It depends on the content: typically carries H.264/AVC or H.265/HEVC video with AAC audio, though the box structure also accepts AV1, MP3, and timed-text tracks. Convert one representative file first and compare before batch-processing a large set.
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 MP4 back to MTS?
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .mts → .mp4 → .mts is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.