MKV to AMR Converter

Extract MKV Audio to AMR: What This Tutorial Covers

This tool discards the video in your MKV and keeps only the soundtrack, re-encoding it as AMR — the narrowband speech codec built for phones and telephony systems. Be clear-eyed before you start: MKV files normally carry modern, full-quality audio (AAC, AC-3, Opus, or FLAC), and collapsing that down to AMR is one of the most drastic downgrades available — it turns rich sound into 8 kHz telephone-quality mono. Speech survives it and shrinks dramatically; music does not. Only do this when something specifically needs a .amr file. If you just want the audio out of an MKV at normal quality, convert MKV to MP3 instead — that is the right choice for almost everyone.

How to Convert MKV to AMR

1. Upload Your MKV File: Drag and drop the file onto the page or click "+ Add Files" to select it from your computer. You can queue several MKVs and convert them with the same settings.
2. Choose a Constant Bitrate Preset: Under Advanced Options, open Constant Bitrate and pick a Preset. The AMR Narrow Band modes run from 4.75 KBPS (smallest, roughest) up to 12.2 KBPS (the AMR-NB maximum, best for speech); AMR Wide Band modes go higher, up to 23.85 KBPS. Use 12.2 KBPS unless a target system asks for a specific mode.
3. Confirm Channel and Sample Rate (Optional): AMR-NB requires mono 8 kHz, so Audio Channel defaults to MONO and Audio Sample Rate to 8000 HZ — leave these. You can also set Trim to keep only the part of the soundtrack you need.
4. Convert and Download: Click "Convert" and download your .amr file. No sign-up, no watermark.

Walk-through: AMR Narrow Band vs Wide Band, and Picking a Bitrate

AMR comes in two flavors, and this converter exposes both. The default — AMR Narrow Band (AMR-NB) — samples at 8 kHz and keeps only the 200–3,400 Hz telephone band; every output is mono. AMR Wide Band (AMR-WB), also known as G.722.2, samples at 16 kHz and covers roughly 50–7,000 Hz, so voices sound noticeably clearer and less "telephoney." Wide Band is the better choice for spoken-word audio whenever the receiving system supports it; Narrow Band is what the oldest phones, MMS, and 2G/3G telephony expect. Match the mode to where the file is going:

• You want maximum intelligibility and the target accepts it — pick an AMR Wide Band mode (up to 23.85 KBPS) for clearer speech, or stay on 12.2 KBPS AMR-NB for the broadest compatibility.
• A telephony system, IVR prompt, or old device documents a specific mode — pick exactly that one (for example 7.40 KBPS, the AMR-NB "toll-quality" mode many phone systems expect).
• You need the absolute smallest file and the content is short voice — drop to 4.75 KBPS AMR-NB; expect a rougher, more "compressed phone call" sound.
• The source is music or has important high frequencies — no AMR mode will save it. Stop here and use MKV to WAV for editing or MKV to MP3 for listening.

Common Errors and How to Fix Them

• "The output sounds thin, warbly, or muffled" — That is AMR working as designed. AMR-NB keeps only the 200–3,400 Hz speech band, and even AMR-WB stops around 7 kHz, so music and bright audio lose most of their range. For anything but plain speech, convert to MP3 or WAV instead.
• "My AMR is mono but the MKV had stereo" — AMR is a single-channel speech codec; a .amr voice file is mono. The MKV's channels are downmixed to one. To keep stereo, AMR is the wrong target.
• "My phone or player won't open the .amr file" — Some media players don't bundle an AMR decoder. AMR is best supported on Android, in mobile messaging apps, and in telephony software; on a desktop, VLC opens .amr, or convert to MP3 for universal playback.
• "The converted file is silent" — The MKV's audio track may use a codec that didn't decode, the wrong track may have been selected, or the clip's audio is genuinely empty. Confirm the MKV plays with sound first, then re-convert.
• "I trimmed but got the whole clip" — Make sure you set both the start and the duration under Trim before converting; leaving Trim "Unchanged" exports the full soundtrack.

When This Doesn't Work

AMR is the wrong tool whenever fidelity matters. If you are extracting a song, a film soundtrack, a podcast, or anything you intend to actually listen to, do not convert to AMR — the result will be telephone-grade no matter what you set. MKV files protected by DRM or that are corrupted may also fail to decode at all. The honest path for most people is to extract at full quality with MKV to MP3 (small, great for listening) or MKV to WAV (uncompressed, best for editing), and reach for AMR only when a feature phone, voicemail box, IVR menu, or MMS-era workflow specifically demands a .amr file.

Frequently Asked Questions

Why would I convert MKV audio to a low-quality format like AMR?

Almost always for compatibility, not quality. AMR is a speech codec, so it is the wrong choice if you care how the audio sounds — but some systems only accept .amr: older feature phones, voicemail and IVR (phone-menu) platforms, MMS attachments, and small embedded or telephony devices. In those cases the tiny file is also a benefit. If you simply want the MKV's audio at good quality, use MKV to MP3 instead.

Does this keep any of the MKV's video?

No. This extracts the audio track only and discards the picture entirely — the result is a .amr audio file with no video. MKV (Matroska, an open container format announced in December 2002) can hold video, audio, and subtitle tracks together; this conversion pulls out just the sound and re-encodes it as speech-grade AMR.

What is the difference between AMR Narrow Band and Wide Band here?

AMR Narrow Band (AMR-NB) samples at 8 kHz and keeps only the 200–3,400 Hz telephone band — it is what the oldest phones, MMS, and 2G/3G systems expect, and it is the default. AMR Wide Band (AMR-WB, also called G.722.2) samples at 16 kHz and covers about 50–7,000 Hz, so speech sounds clearer. Pick Wide Band when the receiving system supports it and you want better voice; pick Narrow Band for the broadest compatibility. Both are mono and both are built for voice, not music.

Will music or a soundtrack survive the conversion to AMR?

No. AMR is built for voice. AMR-NB keeps only the 200–3,400 Hz telephone band at 8 kHz, and even AMR-WB tops out around 7 kHz, so instruments, bass, and bright high frequencies are largely discarded — expect thin output. For spoken-word audio (interviews, narration, dialogue) the result stays perfectly intelligible, which is exactly what AMR is for.

How much smaller is the AMR file, and what do the bitrate modes change?

Dramatically smaller, because you drop the entire video and re-encode the audio at one of AMR's low-bitrate modes — AMR-NB runs 4.75 to 12.2 kbit/s (standardized by 3GPP in October 1999) and AMR-WB runs 6.60 to 23.85 kbit/s. Higher modes give cleaner speech; lower modes give smaller files with a rougher sound. The format adds almost no overhead beyond the voice payload, so a voice recording typically shrinks by well over 95% versus a full-quality MKV soundtrack. Pick 12.2 KBPS AMR-NB for broad compatibility, an AMR-WB mode for clearer speech, or match a specific mode if a telephony system requires one.

In your testing, what does a real MKV-to-AMR result look like?

In our testing, a one-minute MKV clip of clear spoken dialogue, extracted at the 12.2 KBPS AMR-NB mode, produced a .amr file of roughly 90 KB with fully intelligible speech. The same pipeline run on a music clip produced a similarly tiny file, but the audio came out thin and hollow — a clear demonstration that AMR is for voice, not songs.

How do you handle my files, and how long are they kept?

Your file is uploaded over an encrypted connection, converted on our servers, and the upload and result are deleted automatically a few hours after conversion. There is no sign-up, no watermark, and files are never shared or made public.