Step 1: Drop your AMR 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.
AMR 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 AMR 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. AMR is a narrowband speech codec running between 4.75 and 12.2 kbps, modelling the human vocal tract rather than the full audio spectrum. AC-3 is lossy multichannel audio, normally 5.1 at 384 or 448 kbps, with metadata for dialogue normalisation and downmixing.
Why does music sound so poor in this conversion?
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Because one side of it is a speech codec rather than a music codec. It models the human vocal tract and discards everything outside telephone bandwidth, which is fine for a voice memo and destructive for anything with instruments in it. Converting away from it cannot restore the missing frequencies — they were never encoded in the first place. AMR destroys music: its 8 kHz bandwidth removes everything above telephone frequencies, and no amount of re-encoding brings it back.
Will going from AMR to AC3 reduce my audio quality?
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If AMR is lossy and AC3 is lossless (e.g. MP3 → WAV), the AC3 file is no better than the AMR — you can't recover information that's already been thrown away. If AMR 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 AMR 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 AMR?
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By default yes (48 kHz AMR → 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 AMR 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 AMR file private during conversion?
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Yes. Nobody listens to or shares the audio, which matters for personal audiobook libraries, and uploaded AMR files and their converted copies are deleted automatically about 24 hours after conversion.
How long does converting a 10-hour audiobook AMR to AC3 take?
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It depends on the size and length of the file. Small documents and images are usually ready quickly. Long videos take the longest, because most video conversions re-encode every frame.
