Step 1: Provide your MP4 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.
MP4 to AMR Conversion FAQ
How do I extract just the audio track from MP4 as AMR?
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Upload the MP4 file and the converter demuxes the audio stream from the MP4 container, then transcodes it into AMR. Video frames are discarded — no second video pass, no quality loss beyond what the AMR codec itself introduces. 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.
Which audio track gets extracted when my MP4 has several?
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One track, picked automatically: normally the main one, the track with the most channels. This page has no setting to choose a different track and does not list the tracks in the file. If you need commentary or a dub instead, remux the MP4 with that track first (VLC or ffmpeg can do this) and convert it again.
What bitrate does the AMR file 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 going from MP4 to AMR reduce my audio quality?
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If the AMR format is lossless (WAV, FLAC, ALAC), every original sample is preserved. If AMR is lossy (MP3, AAC, OGG, Opus), the codec recompresses — at 192 kbps the difference is inaudible for most content; at 96 kbps you may hear cymbals or sibilants softening. The MP4 container has no influence on this — only the codec settings matter.
Does the extracted AMR keep the MP4 sample rate?
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By default yes — 48 kHz MP4 audio becomes 48 kHz AMR audio, 44.1 kHz becomes 44.1 kHz. If you need to downsample for compatibility (e.g. 96 kHz studio masters to 44.1 kHz CD-quality AMR) the sample-rate dropdown does this with high-quality resampling.
Can I batch-extract AMR audio from a folder of MP4 files?
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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 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.
Is my MP4 private during 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 my AMR have silent gaps or wrong audio?
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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.
