AVCHD to MTS Converter

AVCHD to MTS Converter

Here is the part most "AVCHD to MTS" tools never tell you: an AVCHD file and a .MTS file are usually the same recording. AVCHD is the Sony/Panasonic camcorder format; .MTS is the file extension that AVCHD uses for its video streams. So "converting" one to the other is not a real format change — at best it re-wraps or re-encodes a stream that is already AVCHD. This page explains the relationship honestly, shows what this converter actually does, and tells you when you do not need it at all.

AVCHD and MTS Are the Same Format

AVCHD (Advanced Video Coding High Definition) stores its footage as MPEG-2 Transport Stream files inside a BDMV/STREAM folder copied from the Blu-ray spec. Those stream files carry the extension .MTS when written by the camcorder and are commonly renamed .M2TS after you import them with software like Sony PlayMemories or Catalyst. The bytes inside are identical: H.264/AVC video plus Dolby AC-3 or linear PCM audio in a transport-stream wrapper. In other words, .MTS ≡ .M2TS ≡ an AVCHD stream — the same way .jfif and .jpg are the same JPEG data under two names.

Because of this, most people searching for "AVCHD to MTS" already have an .MTS file and just need it recognized. Often renaming .avchd (or .m2ts) to .mts is all that is required — no conversion, no quality loss. Use the converter below only when you actually need to re-encode the stream (see "When you actually need this" further down).

AVCHD Format at a Glance

MTS (the .MTS Stream) at a Glance

How to Convert AVCHD to MTS

1. Upload Your AVCHD File: Drag and drop the .MTS, .M2TS, or .avchd stream from your camcorder's BDMV/STREAM folder, or click "Add Files" to pick it from disk. You can queue several clips from one shoot.
2. Pick Quality Preset and Codec: Leave the Preset on "Very High (Recommended)" to keep the original look. Expand Advanced to set the Video Codec (H.264 is the default and matches the source) and Audio Codec (AC-3 or AAC). Because both input and output are H.264 in a transport stream, this is a re-encode of an already-identical format — it adds a small generation loss for no format gain, so only change settings if you specifically need to.
3. Resize or Trim (Optional): Use Video resolution to keep the original 1920×1080, choose a preset, or enter Width × Height. Set a Trim Time Range (start and duration) to export only part of a long take.
4. Convert and Download: Click Convert. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically a few hours after conversion — no sign-up, no watermark, never shared.

When You Actually Need This (and When You Don't)

Re-encoding AVCHD to .MTS does not improve compatibility, because the output is the same H.264-in-transport-stream you started with. The honest reasons to run it are narrow: normalizing a stream whose bitrate, resolution, or audio codec you want changed; rebuilding a problematic or slightly corrupt-feeling clip so it carries a clean, freshly written index; or trimming a long recording. If you simply need the file to be .MTS, rename the extension instead. And if your real goal is editing or sharing, AVCHD/.MTS is the wrong target entirely — convert to AVCHD to MP4 for editor and social-platform compatibility, or see the reverse-named MTS to AVCHD if you started from an .mts file.

Frequently Asked Questions

Isn't an AVCHD file already an MTS file?

In almost every case, yes. AVCHD stores its video as .MTS stream files inside BDMV/STREAM, so an "AVCHD file" and an ".MTS file" are the same recording with the same H.264 + AC-3 data. If your camcorder or software labeled the upload .avchd or .m2ts, renaming it to .mts typically makes it recognized — no re-encoding needed.

Does converting AVCHD to MTS lose quality?

A plain rename loses nothing because no bytes change. This online converter, however, re-encodes the H.264 video on the Quality Preset you pick, 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), choose the Highest or Very High preset to keep the result visually indistinguishable from the source.

What is the difference between .MTS and .M2TS?

It is the same data under two extensions. Camcorders write .MTS directly to the SD card; importing with Sony PlayMemories, Catalyst, or AVCHD-aware tools renames the file to .M2TS. Both are MPEG-2 Transport Streams carrying H.264 video and Dolby AC-3 or PCM audio, and this converter accepts either alongside .avchd.

Why can't I just edit my MTS file directly?

.MTS plays fine in VLC or Windows Media Player, but many editors choke on it because the standalone stream lacks the playlist and clip-index data that the full AVCHD folder provides. That is a reason to convert to an editing-friendly container like MP4 — not to .MTS. For that, use AVCHD to MP4, which outputs H.264 + AAC that drops onto any timeline.

Will AVCHD 2.0 1080/60p footage survive the conversion?

Yes. AVCHD 2.0 added 1080p50 and 1080p60 progressive modes at up to 28 Mbit/s in 2011, and the converter preserves the 50/60 fps progressive frame rate. Keep the Preset on Very High or Highest and either retain the original resolution or pick the 1080p preset.

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

In our testing, feeding a camcorder .MTS clip back through this converter at the Very High preset produced another H.264 transport stream that played identically but was a fresh re-encode rather than a byte-for-byte copy — useful for normalizing a flaky file, pointless if the original already played correctly. That is why we recommend renaming over re-encoding whenever the stream 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 do not 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.