Step 1: Share your MP4 files using the button above or by drag and drop.
Step 2: Click the 'Transform' button to start the transformation.
Step 3: Grab your converted AMR files.
MP4 to AMR Transformation FAQ
How do I extract the audio from my MP4 file as AMR?
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Upload the MP4 file and the converter demuxes the audio stream, then transcodes it to AMR. There is no second video pass — the visual track is discarded immediately so extraction is much faster than a full re-encode. MP4 is ISO/IEC 14496-14, standardised in 2001 and derived from the same QuickTime box layout MOV uses. AMR is Adaptive Multi-Rate, the speech codec 3GPP standardised for GSM voice calls and mobile voice recorders.
Is converting MP4 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. Almost every MP4 in the wild is H.264 video with AAC audio; the container also legally holds HEVC, AV1 and VP9. 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. MP4 only supports one widely-honoured subtitle format (mov_text), and multi-track audio is unreliable outside desktop players.
What audio bitrate does the extracted AMR use?
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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.
Will I lose audio quality going from MP4 to AMR?
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If AMR is lossless (WAV, FLAC), every sample is preserved exactly. If AMR is lossy (MP3, AAC, OGG, Opus), the AMR codec recompresses the source audio — at 192 kbps the result is transparent for almost all content. Going lossy → lossless never recovers detail already discarded.
Can I extract audio from multiple MP4 files to AMR in one batch?
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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.
How long does extracting AMR audio from a 1-hour MP4 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.
Can I extract just a section of the MP4 audio as AMR?
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Not in this tool directly — extract the full audio as AMR, then use /audio-trim/ or /audio-cutter/ to clip the section. The two-step path is usually faster than a combined operation and gives you precise waveform-level control.
Is my MP4 file private during the audio extraction?
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Yes. Uploaded MP4 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.
Why does the AMR file have silent gaps where the MP4 had sound?
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Usually the MP4 carries more than one audio track and the one that was converted is silent or secondary. The converter picks one audio track automatically, normally the main one, and this page has no setting to choose a different track. If the wrong one comes out, remux the MP4 with the track you want first (VLC or ffmpeg can do this) and convert it again.
