Step 1: Drop your M4A files using the button above or by deposit and leave.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Receive your converted AC3 files.
M4A to AC3 Conversion FAQ
What bitrate does the AC3 file use?
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A lossy AC3 is encoded at 192 kbps by default. The Audio Quality setting also offers 320 kbps for the best quality and 128 kbps for a smaller file. A lossless AC3 (WAV, FLAC) ignores the bitrate and keeps every sample.
Is converting M4A to AC3 a second round of lossy compression?
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Yes, and it is worth planning around. Both formats are lossy, so the AC3 encoder is working from audio that has already been through one psychoacoustic pass, and its own decisions compound the first set. At 192 kbps or above the result is still transparent for most listening. If you have a lossless master anywhere, encoding the AC3 from that instead avoids the double pass entirely. An M4A holds AAC in most cases, or Apple Lossless (ALAC) when it came from a lossless rip. AC-3 is lossy multichannel audio, normally 5.1 at 384 or 448 kbps, with metadata for dialogue normalisation and downmixing.
Will my track titles and album art survive the M4A to AC3 conversion?
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Not intact. M4A carries a proper metadata block, but AC3 has no standard place for artist, album, track number or cover art, so tags are dropped rather than mangled. Keep the M4A as the tagged copy, or re-tag afterwards with a tool like Mp3tag or MusicBrainz Picard. AC-3 is inefficient by modern standards and is not accepted by browsers, phones or most web players without a downmix to stereo.
Why will some of my M4A files not convert?
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DRM. A subset of M4A files are encrypted by the store or the software that issued them, and encrypted audio cannot be decoded by any converter. Anything you ripped yourself, recorded, or bought without protection converts normally; a licensed purchase will not. M4A hides two very different things behind one extension — lossy AAC and lossless ALAC — and non-Apple hardware support is inconsistent.
Will going from M4A to AC3 reduce my audio quality?
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If M4A is lossy and AC3 is lossless (e.g. MP3 → WAV), the AC3 file is no better than the M4A — you can't recover information that's already been thrown away. If M4A is lossless and AC3 is lossy, expect the AC3 codec to recompress; at 192 kbps this is transparent for most content.
Can I batch convert hundreds of M4A files to AC3?
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Several files in one job need a paid plan. Free use is one file per conversion, one conversion an hour. On a paid plan you can add several files to one job, then download each result on its own or all of them in one ZIP.
Will the AC3 keep the same sample rate as M4A?
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By default yes (48 kHz M4A → 48 kHz AC3). If you need to downsample for compatibility (e.g. 96 kHz → 44.1 kHz for CD burning) the advanced sample-rate option does this with high-quality resampling.
Can I normalize loudness in the M4A to AC3 step?
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Not in this step. The converter has no loudness setting and leaves the level as it is. To even out the volume, run the finished AC3 through a Normalize tool on this site.
Will the AC3 play on my car stereo / iPod / audiobook app?
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MP3 plays almost everywhere. AAC plays on Apple devices, most Android phones and Sonos. FLAC plays on Sonos and Android but not on older iPods, and WAV plays on nearly everything but makes large files. There are no device presets on this page, so choose the target format your player supports.
Is my M4A file private during conversion?
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Yes. Nobody listens to or shares the audio, which matters for personal audiobook libraries, and uploaded M4A files and their converted copies are deleted automatically about 24 hours after conversion.
