MTS to MKV Converter

How to Convert MTS to MKV Online

1. Upload Your MTS File: Drag and drop or click "Add Files" to pick the.mts clips your AVCHD camcorder wrote to its PRIVATE/AVCHD/BDMV/STREAM folder. Batch is supported, so you can drop the whole 00001.mts, 00002.mts, 00003.mts sequence from one shoot.
2. Pick Video Codec and File Compression: Default video codec is H.264 (matches the AVCHD source — re-encode stays fast). Switch to H.265/HEVC for roughly 40-50% smaller files at the same visual quality, or AV1 if your Plex/Jellyfin clients decode it. Under File Compression, the default Quality Preset of "Very High (Recommended)" is the safe choice; pick Constant Quality (CRF) and enter 18-23 for near-visually-lossless H.264, or set a Target file size (%) / Specific file size (MB) when you have a storage cap.
3. Audio Codec, Resolution, Trim (Optional): Audio Codec defaults to AAC. Set it to AC3 to keep the camcorder's original Dolby Digital stream byte-for-byte, or FLAC for a lossless re-encode. Under Video resolution, use Keep original for archival, or pick a Preset Resolution (2160p, 1080p, 720p, 480p) when downscaling for a tablet library. Under Trim, switch from Unchanged to Time Range and enter Start Time + Duration (HH:MM:SS.sss) to cut out a single segment.
4. Convert and Download: Click Convert. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared.

Why Convert MTS to MKV?

MTS is the on-card file extension AVCHD camcorders write — Sony, Panasonic, Canon, and JVC have shipped AVCHD hardware since the format was introduced jointly by Sony and Panasonic in 2006. The stream itself is H.264/MPEG-4 AVC video paired with Dolby AC-3 or uncompressed LPCM audio, recorded at up to 24 Mbit/s for standard 1080p modes and up to 28 Mbit/s for 1080-line 50p/60p. Picture quality is genuinely good; the problem is that the.mts container, the spanning playlist files, and the BDMV/STREAM folder structure are awkward for software outside dedicated camcorder tools. MKV (Matroska, released December 2002, freely licensed) accepts any video and audio codec, holds an unlimited number of tracks, supports chapters, and is the de facto container for Plex, Jellyfin, Emby, Kodi, and mpv libraries.

• Plex / Jellyfin / Emby home media servers — These platforms read MKV with chapter markers and multiple audio tracks natively;.mts files often fail to index or trigger transcoding even when the underlying H.264 stream is fine. Converting (or remuxing) to MKV usually means Direct Play instead of CPU-pegging transcodes.
• Open-source editors — Kdenlive, Shotcut, and the free build of DaVinci Resolve handle MKV more reliably than.mts, especially when AVCHD clips have been spanned across the 4 GB FAT32 boundary that SDHC cards enforce.
• Long-term archival — MKV's specification is freely published and the libraries are LGPL/BSD-licensed, so files remain readable by future open-source tools even if a particular vendor's camcorder software is abandoned.
• Multi-track sound — Add a commentary track, dub, or alternate-language mix alongside the original AC-3 from the camcorder mic in a single MKV file, instead of juggling sidecar audio.
• Subtitle support — MKV holds soft subtitles in SRT, ASS/SSA, VobSub, and PGS; AVCHD's subtitle pathway is limited and rarely round-trips through editing.
• Skip the BDMV folder dance — One self-contained.mkv per clip, with no PRIVATE/AVCHD/BDMV/STREAM hierarchy or.cpi/.mpl sidecars to keep in sync.

MTS (AVCHD) vs MKV (Matroska) — Format Comparison

Codec and Quality Quick Guide

Frequently Asked Questions

Will I lose quality converting MTS to MKV?

If you change the video codec (H.264 → H.265/AV1) or set a low Quality Preset, yes — re-encoding always introduces some loss. To stay visually indistinguishable from the camcorder original, keep Video Codec on H.264, set Constant Quality (CRF) to 18 or use the "Highest" Quality Preset, and leave Audio Codec on AC3 so the original Dolby Digital track passes through. The MTS-to-MKV step itself is just a container swap; loss only enters when codecs change.

Can I just remux MTS to MKV without re-encoding?

True stream-copy remuxing (zero quality loss) requires tools like MKVToolNix or ffmpeg's -c copy flag. The xconvert pipeline always re-encodes through the chosen codec, which is why you should keep Video Codec on H.264 and choose the "Highest" preset to minimize any visible difference. If you specifically need a byte-perfect remux of the H.264 elementary stream, MKVToolNix (free, open source) is the right tool — but for 99% of Plex/editing use cases, a high-quality H.264 re-encode is indistinguishable from the source.

My camcorder split one clip into 00001.mts, 00002.mts, 00003.mts — what do I do?

That's the AVCHD spanning behavior — SDHC cards are FAT32, so the camcorder breaks a recording at the 4 GB boundary and writes the next chunk to a new file. Concatenate them first (DOS: copy /b 00001.mts + 00002.mts + 00003.mts joined.mts, or use ffmpeg's concat demuxer) and upload the joined.mts here. Splitting on the byte boundary is clean because AVCHD splits at GOP boundaries.

How do I keep the original AC-3 (Dolby Digital) audio?

Set Audio Codec to AC3 instead of the default AAC. MKV carries AC-3 natively and Plex / VLC / Kodi all decode it; you avoid the slight quality hit of an AAC re-encode and you keep 5.1 channels intact. If your MTS has LPCM audio (some Panasonic and Sony broadcast modes), pick FLAC for a lossless re-encode or PCM s16le to keep it uncompressed.

H.264, H.265, or AV1 for my Plex library?

H.264 is the safest — every Plex client Direct Plays it without transcoding. H.265/HEVC gives roughly 40-50% smaller files at equivalent visual quality but only newer clients (Apple TV 4K, recent Chromecast, Roku Ultra, modern smart TVs) Direct Play it; older clients will trigger CPU-heavy transcodes on your server. AV1 is even more efficient but client support is still limited in 2026 — fine for cold archives, not yet ideal for live streaming to a mix of devices.

Why is my MKV bigger than the original MTS?

Two common causes. First, if you bumped Quality Preset to "Highest" or set CRF below 18 on H.264, the encoder is preserving more detail than AVCHD's 17-24 Mbit/s baseline. Second, if Resolution Percentage is set above 100% or you changed Audio Codec to FLAC (lossless) from the source AC-3 (lossy), the new file genuinely contains more data. Drop CRF to 20-23 or use the "Very High" preset and stick to AC3 audio to land below the source size.

Will my video editor recognize MKV?

Open-source editors handle MKV well: Kdenlive, Shotcut, OpenShot, and DaVinci Resolve all import it. Adobe Premiere Pro and Final Cut Pro historically prefer MOV or MP4; if those are your tools, convert MTS to MOV or convert MTS to MP4 instead. For Resolve specifically, MKV imports work but the official supported list is MP4/MOV/MXF.

Should I trim before or after conversion?

Trim during conversion using the Trim → Time Range option in step 3 — it's faster than a full re-encode of the whole clip followed by a separate cut, and it avoids generating a giant intermediate file. Enter Start Time and Duration in HH:MM:SS.sss format. For more complex multi-cut workflows, do the conversion first and use Trim MTS or import the resulting MKV into an editor.

Is MKV better than MP4 for camcorder footage?

For Plex/Jellyfin/Kodi libraries, archival, multiple audio tracks, and soft subtitles: MKV. For sharing on phones, smart TVs without Plex, social media uploads, and broad device compatibility: MP4. They wrap the same H.264 video stream — pick by playback target. See MTS to MP4 for the MP4 path, or compress MKV if you've already converted but need a smaller file.