MTS to AC3 Converter
FileFlip converts MTS to AC3 entirely inside your browser, using FFmpeg compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert an MTS file to AC3?#
- Drop your MTS file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to AC3 and the conversion starts on its own. FileFlip downloads 30.8 MB of WebAssembly the first time and nothing after that, then runs FFmpeg on your own machine.
- Save the AC3 file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting MTS to AC3 lose quality?#
It depends on what is inside the file. MTS is a container rather than a codec, so whether the AC3 conversion copies the streams across untouched or re-encodes them is decided by the codecs that particular file happens to use.
Is it safe to convert MTS files online?#
Yes, because nothing is uploaded. FileFlip converts MTS files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What MTS to AC3 actually does to the file#
Converting MTS to AC3 runs on FFmpeg, downloads 30.8 MB of WebAssembly the first time and nothing after that, re-encodes or copies through depending on the codecs in the file, and drops encoded streams and video tracks.
| Engine | FFmpeg |
|---|---|
| Conversion path | One step: MTS → AC3 |
| Downloaded to your browser | 30.8 MB, once, then cached by your browser |
| Quality | Decided by the codecs inside the file |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Encoded streams | Dropped | The target format has nowhere to put it. |
| Video tracks | Dropped | The target format has nowhere to put it. |
What is an MTS file?#
An MTS file holds the same BDAV MPEG-2 transport stream as M2TS, written under the extension the AVCHD standard assigns to footage recorded straight onto a camcorder's memory card.
Keep footage as MTS straight off a camcorder while it's only being copied or archived, since re-encoding at that stage only costs quality for no benefit.
Convert MTS to MP4 before editing or sharing camcorder footage, since most editors and every modern device handle MP4 more smoothly than the camcorder's native transport stream.
What is an AC3 file?#
An AC3 file holds a Dolby Digital bitstream, the compressed multi-channel audio format Dolby Laboratories introduced in 1991 for cinema and later carried onto DVD, Blu-ray discs, and digital television broadcasts.
Keep audio as AC3 when it is a DVD, Blu-ray, or broadcast track destined for a home theater receiver that decodes Dolby Digital natively.
Convert AC3 to AAC, MP3, or WAV when the audio needs to play on a phone, a laptop, or in a web page, none of which decode Dolby Digital on their own.
MTS to AC3 questions people ask#
What produces an MTS file?
MTS files come off consumer and prosumer camcorders recording in the AVCHD format, made by Sony, Panasonic, Canon, and others since 2006. The camera writes each clip into the memory card's AVCHD folder structure with the .MTS extension.
Why won't my MTS file import into my video editor?
Some editors read the AVCHD folder structure a camcorder card uses but choke on an MTS file copied out on its own, and others simply don't ship the H.264 decoder settings AVCHD needs. Copying the whole camera folder in through the editor's dedicated camera-import feature, or converting the MTS to MP4 first, usually clears it up.
What's the difference between MTS and M2TS?
Nothing in the stream itself. Both are the same BDAV MPEG-2 transport stream; MTS is the extension the AVCHD camcorder standard uses for footage on a memory card, while M2TS is the extension Blu-ray Disc authoring and playback software uses for the same structure once it's on a disc.
What should I convert MTS to?
Convert MTS to MP4 for editing and playback outside camcorder-specific software. It carries the same H.264 video without the AVCHD packaging that trips up general-purpose editors and players.