Step 1: Provide your AC3 files using the button above or by toss and let go.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Fetch your converted AMR files.
AC3 to AMR Conversion FAQ
What bitrate does the AMR file end up at?
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A lossy AMR 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 AMR (WAV, FLAC) ignores the bitrate and keeps every sample.
Is converting AC3 to AMR a second round of lossy compression?
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Yes, and it is worth planning around. Both formats are lossy, so the AMR 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 AMR from that instead avoids the double pass entirely. AC-3 is lossy multichannel audio, normally 5.1 at 384 or 448 kbps, with metadata for dialogue normalisation and downmixing. 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.
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. AC-3 is inefficient by modern standards and is not accepted by browsers, phones or most web players without a downmix to stereo.
Will going from AC3 to AMR actually reduce my audio quality?
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If AC3 is lossy (MP3, AAC) and AMR is lossless (WAV, FLAC), the AMR is no better than the AC3 — you cannot recover information already discarded by the lossy AC3 codec. If AC3 is lossless and AMR is lossy, expect the AMR encoder to recompress; at 192 kbps the loss is imperceptible to most ears.
Can I batch-convert hundreds of AC3 files into AMR?
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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.
Can I normalize loudness in the AC3 to AMR 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 AMR through a Normalize tool on this site.
Will the AMR play on my car stereo / iPod / Sonos / Bluetooth speaker?
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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. AMR makes voice recordings absurdly small — an hour of speech fits in a few megabytes — and it is what many phones still record calls in. AMR destroys music: its 8 kHz bandwidth removes everything above telephone frequencies, and no amount of re-encoding brings it back.
Is my AC3 file private during conversion?
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Yes. Uploaded AC3 files are processed on our own conversion servers, no person reviews them, and they are never shared. The upload and the converted AMR are both deleted automatically about 24 hours after the conversion, which leaves time to download the result. See /privacy/ for the full policy.
How long does converting a 1-hour AC3 to AMR 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.
