MP4 to AMR Converter

How to Convert MP4 to AMR Online

1. Upload Your MP4 File: Drag and drop or click "Add Files" to select .mp4 or .m4v files. Phone screen recordings, GoPro clips, Zoom or Teams meeting exports, dashcam footage, podcast video uploads, and YouTube downloads all work — only the audio track is extracted, the video is discarded. Batch upload is supported.
2. Pick AMR-NB or AMR-WB and a Bitrate: Default is AMR-NB at 12.2 kbps — the highest-quality narrowband mode (8 kHz sample rate) used by GSM telephony and most pre-2010 phones. Drop to 7.40 or 4.75 kbps for ultra-small voicemail-style files. Switch to AMR-WB (16 kHz wideband, also called HD Voice) and pick 12.65, 15.85, or 23.85 kbps when the source has clear dialogue worth preserving, or 6.60 kbps for the smallest wideband output.
3. Set Sample Rate, Channels, and Trim (Optional): AMR is locked to 8 kHz (NB) or 16 kHz (WB) and is always mono — the encoder downmixes stereo and resamples automatically. Use the trim section to enter a start time and duration in seconds or HH:MM:SS.sss format if you only need a slice of the dialogue (cutting one line out of an interview, removing intro music before the speech, or chopping a long meeting down to a single quote).
4. Convert and Download: Click Convert. Files process in your browser session and download individually or as a ZIP — no sign-up, no watermark, no upload to a third-party server.

Why Convert MP4 to AMR?

MP4 is the dominant container for video on phones, cameras, and the web — it typically wraps H.264 or H.265 video alongside an AAC stereo audio track at 128-256 kbps. AMR (Adaptive Multi-Rate) is the speech codec used by GSM, UMTS, and VoLTE phone networks; it compresses voice down to 4.75-23.85 kbps by modeling the human vocal tract instead of sampling the waveform. Pulling the audio out of an MP4 and re-encoding it as AMR is overwhelmingly a speech-only workflow. Common reasons to do it:

• Custom phone ringtones and notification tones for older handsets — feature phones, Symbian devices, and pre-2012 Android handsets accept .amr ringtones natively but reject MP3 or M4A. A 5-second AMR-NB clip is around 7 KB, small enough to ship as an MMS attachment or load into a phone's tiny ringtone slot.
• MMS voice attachments and carrier voicemail systems — MMS gateways and many voicemail storage backends still accept only AMR-NB. Converting an MP4 dialogue clip into AMR makes it sendable as an MMS voice note on networks that strip other audio formats.
• IVR prompts and call-center voice menus — Asterisk, FreeSWITCH, and many SIP/PBX systems prefer AMR-NB or AMR-WB for prompts because that's what codec negotiation lands on. Converting MP4 narration straight to AMR avoids a decode/transcode step at call time.
• Field-recorded voice notes from phone video — people frequently record memos, interviews, or quick reminders as MP4 video on a phone (camera app left in video mode) and only need the speech afterward. AMR compresses a one-hour MP4 voice memo from 200-500 MB down to 3-5 MB.
• Speech-recognition training data and forensic audio archives — research datasets and law-enforcement evidence systems sometimes mandate AMR-NB to mirror what a real phone call would have captured. Converting MP4 source material to AMR simulates that channel for testing.
• Push-to-talk and 2G/EDGE radio relays — bandwidth-starved deployments (satellite radio, remote monitoring, some PTT apps) pick AMR for its tiny payload. Extracting the speech track from an MP4 briefing or instructional video produces the right format directly.

If the destination needs a more universal format, see MP4 to MP3 or MP4 to WAV. For the reverse extraction from a different video container, MPEG to AMR covers MPEG-1/MPEG-2 sources, and AMR to MP3 goes the other direction.

MP4 vs AMR — Format Comparison

AMR Bitrate Quick Guide

Frequently Asked Questions

Should I pick AMR-NB or AMR-WB when extracting from MP4?

Pick AMR-NB if the target is a feature phone, MMS gateway, GSM voicemail, or any pre-2010 mobile network — those endpoints almost always assume narrowband. Pick AMR-WB (HD Voice) if the destination is a modern VoLTE-capable phone, a SIP softphone, or an Asterisk/FreeSWITCH PBX configured for wideband. AMR-WB at 12.65 kbps sounds noticeably clearer for dialogue than AMR-NB at 12.2 kbps because it captures up to 7 kHz of audio versus 3.4 kHz, but it is not universally accepted on older handsets.

Will music or background sound in my MP4 survive the AMR encode?

No. AMR is a speech-only codec built around the ACELP algorithm — it models the vocal tract and discards everything outside the speech band. Music, sound effects, and ambient noise come out muffled, warbly, and chorus-like, and percussion turns to mush. If your MP4 has any musical content worth keeping, convert to MP3 or M4A instead. Use AMR only when the source is pure speech.

Why is the AMR file so much smaller than the original MP4?

Two reductions stack. First, you are discarding the video track entirely — that is typically 90-98% of an MP4 file. Second, you are re-encoding the remaining audio from a 128-256 kbps full-spectrum stereo AAC stream down to a 4.75-23.85 kbps speech-band mono stream, another 10-50× reduction. A 200 MB MP4 with 60 seconds of dialogue becomes a 35-90 KB AMR-NB file or a 50-180 KB AMR-WB file.

Is the output mono or stereo?

Always mono. AMR has no stereo mode — the encoder downmixes the source automatically. This is fine for ringtones, MMS, IVR, and telephony, which are all mono pipelines anyway. If you need stereo speech output, convert to MP3 or AAC instead.

What sample rate does the encoder produce?

8 kHz for AMR-NB and 16 kHz for AMR-WB. There is no other option — these are the rates the codec specification defines. The MP4's source audio (44.1 or 48 kHz AAC) is automatically downsampled before encoding. If you need a different sample rate, AMR is not the right format for your use case.

Can I batch convert a folder of MP4 files at once?

Yes. Drop in multiple .mp4 or .m4v files and each converts in parallel within your browser session. Output downloads as individual AMR files or as a single ZIP. Useful when batch-prepping IVR prompts from a folder of recorded scripts, building a corpus of speech samples for an ASR test set, or converting screen-recorded tutorials into compact voice-only briefings.

Can I trim the MP4 before converting to AMR?

Yes. Use the trim section to enter a start time and duration. Both accept seconds (12.5) or HH:MM:SS.sss format (00:01:30.500). This is useful for cutting a single line of dialogue out of a long MP4, skipping past the title card or intro music, or chopping a multi-minute clip down to the few seconds you actually want as a ringtone.

Will the AMR play on iPhone or modern Android?

Modern iOS and Android no longer ship a native AMR player in the default Files or Music app — Apple removed AMR support around iOS 11, and stock Android dropped it in recent releases. The file still works in VLC, Audacity, and most third-party media players, and it remains valid for MMS, ringtone slots on older phones, and any backend system (Asterisk, FreeSWITCH, IVR platforms) that expects AMR. If you need a file that just plays on a current consumer phone, use MP4 to MP3 instead.