Extract Audio from HEVC to AMR — Free Online Tool
Extract audio from HEVC/H.265 video files and convert it to AMR format using the libopencore_amrnb codec — ideal for isolating speech from high-efficiency video for use in mobile telephony, voice messaging, or low-bandwidth audio applications. This tool runs entirely in your browser via FFmpeg.wasm, so no files ever leave your device.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your HEVC file here
or click to browse
Free — no uploads, no signups. Your files never leave your browser.
Settings
Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
During this conversion, FFmpeg discards the H.265 video stream entirely and extracts only the audio track from the HEVC container. That audio is then re-encoded using the libopencore_amrnb codec (AMR Narrowband) at a bitrate of 12,200 bps — the highest quality AMR-NB mode, equivalent to the GSM EFR standard. Because AMR is a speech-optimized lossy format with a fixed 8 kHz sample rate and very narrow frequency response, the encoder will downsample and mono-mix any audio that doesn't already match those parameters. This means stereo or high-fidelity audio tracks from your HEVC file will be significantly reduced in fidelity — AMR is purpose-built for voice intelligibility, not music or broadband audio reproduction.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg multimedia processing tool. In the browser, this runs via FFmpeg.wasm — a WebAssembly port of FFmpeg — so no installation is required and no data leaves your device. |
-i input.hevc
|
Specifies the input file — an HEVC/H.265 video file. FFmpeg will parse both the video stream (encoded with libx265) and any audio streams present in the container before applying the conversion. |
-vn
|
Disables video output entirely, telling FFmpeg to ignore the H.265 video stream and extract only the audio. Without this flag, FFmpeg would attempt to include video in the output, which AMR cannot contain. |
-c:a libopencore_amrnb
|
Sets the audio encoder to libopencore_amrnb, which implements the AMR Narrowband codec used in mobile telephony. This encoder re-encodes the audio from your HEVC file into the speech-optimized AMR-NB format at 8 kHz mono. |
-b:a 12200
|
Selects the AMR-NB encoding mode MR122, which operates at 12,200 bps — the highest quality and highest bitrate mode available in AMR Narrowband. This corresponds to the GSM Enhanced Full Rate standard and provides the best speech intelligibility within the AMR-NB format's constraints. |
output.amr
|
Defines the output filename with the .amr extension, which tells FFmpeg to write the result in the AMR file container. This file will contain a single mono AMR-NB audio stream and will be compatible with mobile devices, telephony systems, and applications that support the AMR format. |
Common Use Cases
- Extracting spoken narration or dialogue from an H.265 screen recording to send as a voice message on a mobile platform that accepts AMR files
- Converting interview or lecture footage recorded in HEVC on a modern smartphone or camera into AMR for archiving or transcription in a speech-processing pipeline
- Preparing voice content from H.265 video for integration into telecom or IVR systems that require AMR-NB encoded audio
- Stripping audio from HDR or 4K HEVC video files to produce compact AMR voice clips for distribution over low-bandwidth mobile networks
- Extracting the audio commentary track from an H.265 video file to create a lightweight AMR recording compatible with older mobile handsets
- Isolating field-recorded speech from HEVC drone or action camera footage for use in mobile applications requiring AMR format input
Frequently Asked Questions
No — AMR Narrowband (libopencore_amrnb) is specifically engineered for human speech, not music or wideband audio. It operates at a fixed 8 kHz sample rate and outputs mono audio, which means stereo tracks will be mixed down and frequencies above 4 kHz (including most musical content) will be lost entirely. If your HEVC file contains music, sound effects, or high-quality audio, AMR will make it sound thin and telephone-like. This conversion is best suited for voice recordings where intelligibility matters more than fidelity.
Two things contribute to the dramatic size reduction. First, the entire H.265 video stream — which accounts for the vast majority of a typical HEVC file's data — is discarded completely. Second, the AMR-NB codec encodes audio at just 12,200 bps (about 12 KB per second of audio), one of the lowest bitrates of any standardized audio codec. A one-hour HEVC video that might be several gigabytes will produce an AMR audio file of only around 50–55 MB.
AMR-NB (Narrowband) operates at 8 kHz and supports bitrates from 4,750 to 12,200 bps — it is the classic mobile voice standard used in 2G/3G telephony. AMR-WB (Wideband) operates at 16 kHz and offers higher voice quality, often used in HD Voice calls. This tool uses AMR-NB by default (libopencore_amrnb), which offers the widest compatibility with older mobile devices and telecom infrastructure. If your target system supports AMR-WB and you need better speech clarity, you can modify the FFmpeg command to use -c:a libopencore_amrwb with a compatible bitrate such as 23850.
The -b:a flag controls the AMR-NB bitrate. AMR-NB supports only specific fixed bitrate modes: 4750, 5150, 5900, 6700, 7400, 7950, 10200, and 12200 bps — you must use one of these exact values. The default in this tool is 12200 (highest quality). To reduce file size at the cost of speech clarity, you could use -b:a 7950 for a balanced option, or -b:a 4750 for maximum compression. For example: ffmpeg -i input.hevc -vn -c:a libopencore_amrnb -b:a 7950 output.amr
Yes — if your HEVC file contains only a video stream with no audio track (which is common with some raw HEVC captures or video-only files), FFmpeg will throw an error and produce no output because there is no audio to extract. You can check whether your file has an audio stream by running ffmpeg -i input.hevc in your terminal and inspecting the stream list. If no audio stream is listed, this extraction tool is not applicable to that file.
The single-file command shown on this page can be adapted for batch processing on the desktop using a shell loop. On Linux or macOS, you can run: for f in *.hevc; do ffmpeg -i "$f" -vn -c:a libopencore_amrnb -b:a 12200 "${f%.hevc}.amr"; done. On Windows Command Prompt: for %f in (*.hevc) do ffmpeg -i "%f" -vn -c:a libopencore_amrnb -b:a 12200 "%~nf.amr". Batch processing in the browser version would require uploading and converting files one at a time.
Technical Notes
The libopencore_amrnb encoder enforces strict constraints that differ from most other audio codecs: it only accepts mono audio at exactly 8,000 Hz. FFmpeg will automatically apply channel downmixing and sample rate conversion from whatever audio is embedded in your HEVC file, but this resampling is lossy and can introduce artifacts if the source audio is at a very different sample rate (e.g., 48 kHz, which is common in video production). The AMR container (.amr) supports only a single audio track, so if your HEVC file has multiple audio streams, FFmpeg will default to the first one — you can select a different stream with -map 0:a:1 (for the second audio track) in the command. AMR files carry no metadata such as title, artist, or chapter markers. The format also has no concept of variable bitrate — each of the eight AMR-NB modes is a fixed-rate codec mode rather than a true bitrate target, so setting -b:a 12200 selects mode 7 (MR122) rather than allowing flexible encoding. This tool is particularly relevant for developers working with HEVC content from modern smartphones that need to feed audio into legacy telecom or voice-processing systems that predate modern audio codecs.