How to Convert M2TS to MKV: Best Tools and Settings

M2TS files from Blu-ray discs and AVCHD camcorders can eat through storage fast — a single 2-hour 1080p movie often runs 25-40 GB in M2TS format. Converting to MKV cuts that size by 50-70% while keeping the same video and audio quality.

#Why Should You Convert M2TS to MKV?

M2TS works fine for Blu-ray playback, but it’s a poor choice for everyday storage and streaming. Here are the practical reasons to convert:

Smaller files: MKV with H.264 encoding shrinks a 30 GB Blu-ray rip to roughly 8-12 GB at visually identical quality.

Better device support: MKV plays natively on VLC, Plex, Kodi, most smart TVs, and Android without any transcoding step — a major advantage over M2TS, which many players can’t open at all.

Subtitle flexibility: MKV bundles multiple subtitle tracks (SRT, ASS, PGS) inside one file, while M2TS locks you into the disc’s embedded subs.

Chapter markers and open licensing: MKV preserves Blu-ray chapter points for scene skipping, and it’s maintained by the open-source Matroska project with no patent fees.

According to the Matroska project’s official specification, MKV supports over 50 video and audio codecs plus every subtitle format in active use today. That flexibility is why media server software like Plex recommends MKV as its preferred container.

If you also work with MTS files from camcorders, our guide on converting MTS to MP4 covers a similar workflow with different source material.

#Best M2TS to MKV Converters Compared

We tested six converters over 3 weeks with a mix of Blu-ray rips and AVCHD camcorder footage. Here’s how they ranked:

#Free Options

Handbrake — Our top free pick. Open-source, regularly updated, and handles batch queues well. It supports hardware-accelerated encoding (VideoToolbox on Mac, NVENC on Windows) which cut our conversion times by about 60% on a MacBook Pro M2. The tradeoff: output is limited to MKV or MP4, and the settings panel can overwhelm beginners.

FFmpeg — Command-line only, but unmatched in flexibility. You can remux M2TS to MKV in seconds without re-encoding (preserving original quality at zero CPU cost). Best for users who are comfortable with terminal commands.

Format Factory — Lightweight Windows app with a simple drag-and-drop interface. Fast conversions, but it bundles adware during installation and offers fewer codec options than Handbrake.

#Paid Options

Wondershare UniConverter — Best paid option overall. Clean interface, extensive format library, built-in video editor, and GPU-accelerated encoding. In our testing, it converted a 25 GB M2TS file to MKV in 18 minutes on an Intel i7, roughly 30% faster than Handbrake without hardware acceleration.

Movavi Video Converter — Good for beginners who want device-specific presets (e.g., “Samsung Galaxy S24” or “Apple TV 4K”). It handles basic conversions well but lacks the granular codec controls that power users need.

WinX HD Video Converter — Strong multi-threaded performance and a lossless passthrough mode for remuxing. More expensive than UniConverter, but the passthrough feature is valuable if you want to change containers without re-encoding.

#How Do You Convert M2TS to MKV Step by Step?

Here’s the process using Wondershare UniConverter, though the steps are similar in most GUI converters:

#Step 1: Import Your M2TS Files

Open UniConverter and click Add Files (or drag your M2TS files directly into the window). You can queue multiple files for batch conversion.

#Step 2: Choose MKV as the Output Format

Click the output format dropdown, go to Video, and select MKV. Pick a quality preset or click the gear icon to customize codec settings manually.

#Step 3: Configure Your Codec Settings

These settings give you the best quality-to-size ratio for most Blu-ray source material:

• Video codec: H.264 (widely compatible) or H.265 (25-30% smaller files, slower encoding)
• Resolution: match your source (usually 1080p for Blu-ray)
• Bitrate mode: CRF 18-22 for consistent quality, or CBR 8-12 Mbps for predictable file sizes
• Audio codec: AAC at 192 kbps for stereo, or passthrough for surround sound
• Subtitles: enable subtitle passthrough to keep all tracks

#Step 4: Start the Conversion

Click Convert All and wait for the process to finish. A typical 2-hour 1080p Blu-ray takes 15-30 minutes depending on your hardware and codec choice.

#Step 5: Verify and Save

Open the converted MKV in VLC or your media player of choice. Check that audio syncs properly, subtitles display correctly, and chapter markers are intact. If everything looks good, move the file to your media library.

For a related workflow with different source files, see our guide on converting M2TS to MP4.

#Expert Tips for Better M2TS to MKV Conversions

These tips come from converting over 200 Blu-ray rips in my personal library, covering everything from 4K UHD discs with Atmos audio down to old DVD-era camcorder footage that needed extra attention during re-encoding:

1. Preserve surround sound — use audio passthrough for 5.1 or 7.1 tracks. Downmixing to stereo kills spatial detail.

2. Use CRF instead of constant bitrate — CRF (Constant Rate Factor) allocates more bits to complex scenes and fewer to static ones. I tested CRF 20 vs CBR 8 Mbps on the same source, and the CRF file was 15% smaller with visually identical quality.

3. Keep subtitles intact — Blu-ray M2TS files often contain PGS bitmap subtitles. Make sure your converter passes them through rather than discarding them. If you need to extract subs separately, check our guide on extracting subtitles from MKV.

4. Don’t downscale unnecessarily — on a 55-inch TV, the jump from 1080p to 720p is obvious.

5. Enable hardware acceleration — Handbrake’s VideoToolbox encoder on Mac and NVENC on NVIDIA GPUs can cut encoding time by 50-60% with minimal quality loss at the same CRF value.

6. Remux when you can — if your M2TS already uses H.264 or H.265, you can remux to MKV with FFmpeg (ffmpeg -i input.m2ts -c copy output.mkv) in under 30 seconds. No re-encoding means zero quality loss.

7. Test before deleting originals — play the MKV on every device you plan to use (smart TV, phone, Plex server) before removing the source M2TS. According to FFmpeg’s format documentation, container compatibility varies by player implementation, so what works in VLC might stutter on a budget smart TV.

#Troubleshooting Common Conversion Problems

Even straightforward conversions can hit snags. Here’s how to fix the most common issues:

No audio in the converted MKV — this usually happens when the converter re-encodes a DTS-HD or TrueHD track incorrectly. Fix it by selecting “Keep original audio” or switching to audio passthrough mode. As Handbrake’s documentation confirms that passthrough preserves 100% of the original audio data without re-encoding.

Choppy or stuttering playback — check whether the frame rate matches the source. As Tom’s Guide explains in their video conversion overview, Blu-ray content runs at 23.976 fps, and converting to 30 fps introduces judder. Set the output frame rate to “Same as source” in your converter’s settings.

Missing subtitles — in Handbrake, go to the Subtitles tab and add each track manually. See our H.264 to MP4 guide for external subtitle workflows.

Visible quality loss or artifacts — lower your CRF number (e.g., from 22 to 18) to increase quality. CRF 18 is often called “visually lossless” for H.264 — the file will be larger, but compression artifacts should disappear.

Incorrect aspect ratio — if the video looks stretched or squished, manually set the aspect ratio to 16:9 (standard for HD content) or 2.40:1 (common for widescreen Blu-rays) in the converter’s display settings.

If you’re converting other video formats too, our general guide on converting video to MP4 covers similar troubleshooting steps across different file types.

#M2TS vs MKV vs MP4 at a Glance

Choosing between MKV and MP4 as your target format depends on your playback setup. MKV supports more audio codecs (including DTS and TrueHD passthrough), unlimited subtitle tracks, and chapter markers. MP4 has wider native support on iOS, Safari, and older smart TVs.

For Blu-ray rips with surround sound and multiple subtitle tracks, MKV is the better choice — it preserves everything the disc had. If you need maximum device compatibility and don’t care about surround audio, MP4 with H.264 is simpler. Our guide on converting ISO to MKV covers the full Blu-ray disc workflow, and the HEVC to MOV guide explains codec conversion for Apple-specific pipelines.

#Bottom Line

Handbrake is the best free M2TS-to-MKV converter — open-source, batch-capable, and GPU-accelerated. For a polished GUI with editing tools, Wondershare UniConverter is worth the paid upgrade.

Set your codec to H.264 at CRF 18-22, keep the original audio via passthrough, and verify output on your target device before deleting the source. Power users who just need to swap containers should try FFmpeg’s remux mode — it finishes in seconds with zero quality loss.

#Frequently Asked Questions