MTS to AAC Converter

Extract Audio from MTS to AAC Online

MTS is the AVCHD recording format introduced by Sony and Panasonic in 2006 — H.264 video alongside a Dolby Digital (AC-3) or LPCM audio track. This tool pulls the audio out of that clip and writes it as a raw AAC stream with a .aac extension. Unlike an .m4a, this is a bare ADTS elementary stream rather than an MP4 container — the right pick when a tool, encoder, or streaming pipeline expects raw AAC frames rather than a tagged file. The video is discarded; you get audio only.

How to Convert MTS to AAC

1. Upload Your MTS File: Drag and drop your .mts (or .m2ts) clip onto the page or click "+ Add Files". Multiple files queue and convert with the same settings.
2. Set the Quality Preset: Pick a Quality Preset — the default is "Very High (Recommended)" — or switch to Custom Bitrate. Voice and interviews are clean at 96–128 kbps; for music aim for 192–256 kbps to keep the AAC re-encode transparent.
3. Adjust Audio Channel, Sample Rate, or Trim (optional): Leave Audio Channel and Audio Sample Rate on "Original" to match the source, downmix to mono to shrink a voice recording, or use Trim to keep just the segment you need.
4. Convert and Download: Click "Convert" and download your .aac file. No sign-up, no watermark.

Raw .aac vs .m4a — Which Output Do You Want?

Both carry the same AAC codec; the difference is the wrapper. A raw .aac is an ADTS stream of self-synchronizing frames; .m4a is that audio inside an MP4 container.

If you just want to play camcorder audio on a phone or in iTunes, use MTS to M4A instead — same AAC codec, but a tagged, broadly compatible file.

Frequently Asked Questions

What's the difference between this .aac file and an .m4a?

Both hold AAC audio, but the container differs. This tool outputs a raw AAC stream in ADTS framing with a .aac extension — a sequence of self-synchronizing frames with no place to store tags. An .m4a wraps the same AAC audio in an MP4 container that holds metadata (title, artist, artwork) and a seek index. Pick .aac when a downstream tool or stream wants raw AAC frames; pick M4A for everyday playback and tagging.

Why won't my raw .aac file open in some players?

A raw ADTS .aac is not an MP4, so players that expect a container can reject it — QuickTime, for example, will not open raw AAC ADTS files. Most media players (VLC, modern browsers) and audio tools read it fine, but if a specific app refuses the file, convert to M4A or MP3 instead, which use the broadly supported MP4 and MPEG containers.

Will I lose quality extracting AAC from an MTS file?

Yes, a little — this is a re-encode, not a copy. MTS audio is usually Dolby Digital AC-3 (already lossy) or LPCM (lossless). AC-3 to AAC is a lossy-to-lossy step that adds a small amount of generational loss; LPCM to AAC is lossless-to-lossy. In our testing, a stereo AVCHD clip extracted at a 256 kbps AAC preset was indistinguishable from the source in normal listening — the loss only compounds if you re-edit and re-export many times.

Does the .aac file keep any metadata or chapter info?

No. ADTS framing has no field for tags, so title, artist, artwork, and chapter markers are not written to a raw .aac file — that information is lost on export. If you need embedded metadata, choose M4A, whose MP4 container stores tags, or add tags afterward in your own tool.

How are my files handled, and is there a size limit?

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 or made public. The main practical limit is upload size and time: AVCHD clips can be large because they carry full HD video, so a long recording may take a while to upload even though the .aac you get back is small.