M2TS to MTS Converter

Converting M2TS to MTS: Start by Renaming the File

Before you convert anything, know this: .m2ts and .mts are the same format — the BDAV MPEG-2 transport stream that AVCHD camcorders and Blu-ray both use. The .MTS extension is just the 8.3-style short filename a camcorder writes to the SD card; .m2ts is the long-filename form software uses after import. The payload is byte-for-byte identical (H.264 video plus AC-3 or PCM audio), so in most cases renaming file.m2ts to file.mts is all you need — no conversion, no quality loss. This page shows you the rename shortcut first, then explains the narrow cases where the re-encoder below actually helps.

How to Convert M2TS to MTS

1. Upload Your M2TS File: Drag and drop your .m2ts clip onto the page, or click "+ Add Files" to pick it from disk. You can queue several clips from the same shoot and process them with one set of settings.
2. Pick the Quality Preset: Under File Compression, leave Preset on "Very High (Recommended)" to stay close to the source. Expand to set the Video Codec (H.264 is the default and matches an AVCHD source) and Audio Codec — note the default is AAC, so if you want to keep the original AC-3 track choose AC3 explicitly. Because input and output are both H.264 in a transport stream, this is a re-encode of an already-identical format, so only change settings if you have a specific reason.
3. Resize or Trim (Optional): Under Video resolution, keep original (AVCHD is usually 1920x1080), pick a Preset Resolution, or enter custom Width x Height. Use Trim, then Time Range to export just part of a long take.
4. Convert and Download: Click Convert and download your .mts file. No sign-up, no watermark.

Walk-through: The Rename Shortcut vs the Re-encoder

The fastest fix is almost never the converter. Because .m2ts and .mts hold identical bytes, changing the extension makes the file recognized without touching a single frame:

• On Windows: turn on file-extension display (File Explorer → View → File name extensions), then rename clip.m2ts to clip.mts. Nothing re-encodes.
• On macOS: rename in Finder and confirm "Use .mts" when prompted. Same result — a lossless rename.
• When the rename is enough: a media player, TV, or import tool simply refuses the .m2ts name but accepts .mts. The data was always valid; only the label needed to change.

Run the converter above instead only when you genuinely need to change the bits — for example, to normalize a flaky or mixed-bitrate stream into one clean profile, to shrink the file with a lower bitrate or resolution, to trim a long recording, or to re-encode an AC-3 track to AAC for a player that won't decode Dolby. Each of those is a real edit; a plain rename can't do them.

Common Errors and How to Fix Them

• "The output looks the same but the file changed size" — Expected. The converter re-encoded H.264 to H.264, which is a fresh encode, not a copy. If you wanted an identical file, rename instead of convert.
• "My audio went silent after converting" — A downstream player likely can't decode the audio codec. AVCHD commonly carries Dolby AC-3; if your player drops it, re-encode the Audio Codec to AAC, or convert to M2TS to MP4 which pairs H.264 with AAC.
• "My video editor still won't import the .mts" — A bare transport stream lacks the playlist and clip-information sidecar files that the full AVCHD BDMV/STREAM folder provides, and many editors expect those. Converting to MP4 fixes this; converting M2TS to MTS does not.
• "The file is too large to upload or share" — A multi-gigabyte camcorder reel takes time to upload. Lower the bitrate or pick Specific file size under File Compression, or convert to MP4, which is far smaller at similar quality.
• "Convert failed on a Blu-ray rip" — Commercial Blu-ray .m2ts files are usually AACS-encrypted. The converter cannot process protected streams; only unencrypted camcorder recordings or already-decrypted files work.

When This Doesn't Work

If your real problem is compatibility — the file won't play on a phone, browser, TV, or social platform, or won't drop onto an editing timeline — converting M2TS to MTS will not help, because the output is the same H.264-in-transport-stream you started with. The fix is a more widely supported container: convert to M2TS to MP4 for playback and editing everywhere. Encrypted commercial Blu-ray discs and corrupted streams are out of scope for any file converter. And if you have the opposite filename problem — a .mts clip that a tool insists on calling .m2ts — the reverse-named MTS to M2TS covers it (and the rename shortcut works there too).

Frequently Asked Questions

Isn't .m2ts already the same as .mts?

Yes. Both are the BDAV MPEG-2 transport stream carrying H.264 video and AC-3 or PCM audio — the same data under two extensions. Camcorders write the 8.3 short name .MTS to the SD card; computers and Blu-ray use the long name .m2ts. Renaming one to the other is lossless and is usually all you need, which is why we lead with the rename shortcut instead of the converter.

Does converting M2TS to MTS lose quality?

A rename loses nothing because no bytes change. The online converter, however, re-encodes the H.264 video at the Quality Preset you choose, and re-encoding an already-H.264 stream adds a small generation loss for no format benefit. If you must re-encode — to change bitrate, resolution, or audio — keep the Very High or Highest preset so the result stays visually indistinguishable from the source.

Why would I ever run the converter instead of just renaming?

Because a rename only changes the label, not the content. Use the converter when you actually need to alter the bits: normalizing a problematic or mixed-bitrate stream, lowering the bitrate or resolution to shrink the file, trimming a long clip, or re-encoding a Dolby AC-3 track to AAC for a player that can't decode it. If none of those apply, rename and skip the upload entirely.

Will my AVCHD audio survive the conversion?

It depends on the Audio Codec you pick. The default output is AAC, so an original Dolby AC-3 or linear PCM track gets re-encoded unless you select AC3 in Advanced Options. If a downstream player drops AC-3 (a common licensing quirk in consumer software), re-encoding to AAC — or converting to M2TS to MP4 — avoids the silent-audio trap.

In your testing, what does an M2TS-to-MTS re-encode actually change?

In our testing, feeding an unencrypted camcorder .m2ts clip through this converter at the Very High preset produced an .mts file that played identically but was a fresh H.264 re-encode rather than a byte-for-byte copy — genuinely useful for normalizing a flaky stream, and pointless if the original already played correctly. That is exactly why we recommend renaming over re-encoding whenever the source is already healthy.

How are my uploaded files handled and stored?

Files are uploaded over an encrypted (TLS) connection and processed on our servers in an area only the uploading session can reach. We never share, publish, or reuse them, and both the original and the converted file are deleted automatically a few hours after conversion. No sign-up or account is required.