Free online AIF to AMR converter

Some mobile, telephony, messaging, and speech-processing systems require AMR for low-bitrate voice recordings. Converting an AIF file produces a much smaller file for those systems, but speech-oriented compression reduces music quality and cannot be undone.

What AIF is

AIF, also written as AIFF, is the Audio Interchange File Format container developed by Apple. It commonly stores uncompressed PCM audio, although AIFF-C can contain compressed audio. Recording and editing applications such as Apple Logic Pro, GarageBand, Pro Tools, and Audacity can export AIF files.

AIF is suited to production and editing because it can preserve high-resolution source audio, including 16-bit or 24-bit recordings at 44.1 kHz, 48 kHz, or higher sample rates. Uncompressed audio requires substantially more storage than a speech codec, and AIF is not accepted by every mobile or embedded system.

What AMR is

AMR (Adaptive Multi-Rate) is a lossy speech codec and file format used in mobile telephony, voicemail, MMS, embedded devices, and some speech-processing software. It is designed to keep intelligible voice at low bitrates rather than preserve the full frequency range of music.

AMR-NB uses 8 kHz audio and supports bitrates from 4.75 to 12.2 kbit/s. AMR-WB uses 16 kHz audio and supports bitrates from 6.60 to 23.85 kbit/s, providing wider speech bandwidth. The receiving application must support the selected variant; many older systems accept AMR-NB only.

How to convert AIF to AMR

For a one-off conversion, you can use the converter on 101convert.com for free without installing software:

1. Open the converter and select or upload the .aif or .aiff file.
2. Choose AMR as the output format and start the conversion.
3. Download the resulting .amr file and test it in the target phone, application, or device.

Use the service only for recordings whose privacy and handling requirements permit online processing. Keep the original AIF file; the AMR file is a delivery copy, not a replacement master.

Converting with FFmpeg

FFmpeg is suitable for repeatable or batch conversions, provided the installed build includes the required AMR encoder. To create AMR-NB mono speech at the highest standard AMR-NB bitrate, run:

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

Replace input.aif and output.amr with the actual filenames. If FFmpeg reports that libopencore_amrnb is unavailable, install a build compiled with the OpenCORE AMR-NB encoder. To create AMR-WB, use a build containing the VisualOn encoder:

ffmpeg -i input.aif -ac 1 -ar 16000 -c:a libvo_amrwbenc -b:a 12.65k output.amr

The encoder library names and availability depend on the FFmpeg build and operating system. The target application, not the source file, determines whether to use AMR-NB or AMR-WB and which bitrate to select.

Quality and compatibility limits

• AMR conversion is lossy. It removes audio information and cannot be reversed, so convert from the original AIF rather than from an already compressed copy.
• AMR is appropriate for spoken voice, not music, sound effects, or archival masters. Music may sound muffled or distorted even at the highest AMR bitrate.
• AMR-NB normally requires mono, 8 kHz audio; AMR-WB normally requires mono, 16 kHz audio. FFmpeg can downmix stereo input and resample higher-rate AIF audio with -ac and -ar.
• Some software recognizes AMR only when the file has the .amr extension and a valid AMR container. Do not merely rename an AIF file.
• Check the receiving system's required AMR variant, sample rate, bitrate, channel count, and maximum file size before converting.