Free online WAV to AMR converter

Some phones, voicemail systems, and legacy telephony applications accept speech only as AMR, while WAV files are often too large for those systems. Converting the recording reduces its bitrate and produces an .amr file for compatible mobile and voice applications.

What the WAV format is

WAV is a RIFF-based audio container commonly used for uncompressed PCM recordings. PCM WAV preserves the recorded samples without lossy compression; a typical 16-bit, 44.1 kHz stereo file uses about 1.4 Mb/s, or approximately 10 MB per minute. WAV can also contain other codecs, so the file extension alone does not guarantee PCM audio.

Windows Sound Recorder, hardware recorders, CD-ripping software, digital audio workstations, and editors such as Audacity or Adobe Audition commonly create or export WAV files. WAV is useful as an editing or preservation format because it retains more source detail than a speech codec.

What the AMR format is

AMR usually refers to AMR-NB (Adaptive Multi-Rate Narrowband), a speech codec and file format developed for mobile telephony. AMR-NB uses mono audio sampled at 8 kHz and supports eight modes from 4.75 to 12.2 kb/s. Its low bitrate produces files much smaller than typical PCM WAV files.

AMR-NB is intended for speech in voicemail, multimedia messaging, GSM-era mobile software, and other telephony systems. It is not suitable for music, sound effects, or high-fidelity archiving because the 8 kHz bandwidth and lossy compression remove much of the original audio detail.

AMR-WB is a separate wideband codec, normally stored with an .awb extension. Confirm the required format before converting: an application that expects AMR-NB usually requires an .amr file, not AMR-WB.

How to convert WAV to AMR

For a one-off conversion, use the free converter on 101convert.com without installing software. Select the WAV file, choose AMR as the output format, start the conversion, and download the resulting .amr file. If audio options are available, use mono, 8 kHz, and an AMR-NB bitrate supported by the destination system; 12.2 kb/s normally gives the best speech quality, while lower modes produce smaller files.

For local, repeatable conversions, FFmpeg can encode AMR-NB when its build includes the libopencore_amrnb encoder:

ffmpeg -i input.wav -ar 8000 -ac 1 -c:a libopencore_amrnb -b:a 12.2k output.amr

• -ar 8000 resamples the input to AMR-NB's 8 kHz sampling rate.
• -ac 1 downmixes stereo or multichannel audio to mono.
• -c:a libopencore_amrnb selects the AMR-NB encoder.
• -b:a 12.2k selects the highest AMR-NB mode. Other standard modes are 4.75k, 5.15k, 5.9k, 6.7k, 7.4k, 7.95k, and 10.2k.

Check whether the encoder is available with ffmpeg -encoders | grep -i amr on Linux or macOS, or ffmpeg -encoders | findstr /i amr on Windows. If libopencore_amrnb is missing, use an FFmpeg build that provides it or convert with 101convert.com. Renaming input.wav to input.amr changes only the filename and does not encode the audio.

Quality and compatibility limits

AMR encoding is lossy. It cannot restore detail removed by the conversion, so retain the original WAV for editing, preservation, or future exports and use AMR for delivery to systems that require it.

The conversion discards stereo information, downsamples frequencies above the narrowband speech range, and adds codec artifacts. Speech generally remains intelligible at 12.2 kb/s; lower bitrates can sound muffled or robotic. Music and recordings with background effects may degrade severely.

Some current media players do not open AMR without additional codec support. Check the destination application's required extension, codec, sampling rate, bitrate, and MIME type; AMR-NB is commonly identified as audio/amr, while AMR-WB commonly uses .awb.