AAC to AMR Converter

AAC to AMR — Should You Really Convert To It?

For almost everyone, the honest answer is no. AAC is a high-fidelity music codec; AMR is an 8 kHz telephone-quality speech codec, so converting AAC to AMR is a dramatic, audible downgrade — not a way to get "better" or even "smaller, good" audio. Do it only when a specific system demands a .amr file: a voicemail box, an old feature phone, an IVR menu, or embedded telephony hardware. If you just want a smaller AAC file without wrecking it, convert AAC to MP3 or keep AAC instead.

AAC vs AMR — Side-by-side Comparison

Both are lossy, so AAC to AMR is a second generation of loss: the encoder cannot recover detail AAC already discarded, then throws away everything outside the narrow speech band on top of that.

When to Pick AMR

• A system literally requires .amr — voicemail platforms, IVR/auto-attendant prompts, 2G/3G telephony test rigs, and some embedded or two-way-radio firmware accept only AMR.
• Old feature phones — pre-smartphone handsets that record and play voice messages in AMR but can't open AAC.
• Voice memos where size beats fidelity — a minute of speech as AMR-NB is tiny (on the order of tens of kilobytes), which suits SMS/MMS-era workflows and bulk voicemail archives.
• Speech only, never music — narration, dictation, and dialogue stay intelligible; anything with instruments, bass, or stereo does not.

When to Keep AAC (or Convert Elsewhere)

• You want it to still sound good — keep AAC, or use AAC to MP3 for a smaller file that almost any player opens at listenable quality.
• You need lossless for editing — use AAC to WAV so a downstream tool isn't decoding a lossy file.
• You want a modern container, not a new codec — AAC to M4A rewraps the audio without the telephone-band collapse.
• The audio is music, a song, or a soundtrack — no AMR mode will save it; do not convert.

How to Convert AAC to AMR

1. Upload Your AAC File: Drag and drop, or click "+ Add Files" to select one or more .aac files. Batch uploads are supported.
2. Pick the Audio Codec: Under Advanced Options, set Audio Codec to AMR Narrow Band (8 kHz, the default and most compatible) or AMR Wide Band when the target device supports HD Voice and you want clearer speech.
3. Choose a Constant Bitrate (Optional): AMR encodes only at standardized speech rates. Pick an AMR-NB mode from 4.75 up to 12.2 KBPS, or an AMR-WB mode (6.60–23.85 KBPS). Audio Channel is fixed to MONO and Audio Sample Rate to 8000 HZ for AMR-NB; use Trim to keep just the speech you need.
4. Convert and Download: Click "Convert" and download your .amr file. No sign-up, no watermark.

Frequently Asked Questions

Is AMR better than AAC for making audio smaller?

Only in raw bytes, and at a steep cost. AMR-NB is tiny because it discards everything above 3,400 Hz and runs at 4.75–12.2 kbps — fine for a voice memo, ruinous for music. AAC already compresses well at 96–128 kbps while keeping full bandwidth and stereo, so if your goal is a smaller file that still sounds good, stay on AAC or use AAC to MP3 rather than dropping to telephone quality.

Will I lose quality converting AAC to AMR?

Yes, substantially, and in two ways. AAC is already lossy, so re-encoding adds a second generation of loss; on top of that AMR narrows the audio to the 200–3,400 Hz speech band at 8 kHz, mono. Speech stays intelligible, but any music, brightness, or stereo image is gone for good. This is a compatibility conversion, not a quality one.

Can AMR carry stereo or the metadata my AAC file had?

No. AMR is mono by specification, so a stereo AAC track is downmixed to one channel before encoding. AMR is also a bare speech bitstream with no room for cover art, multi-channel layouts, or rich tags. If keeping stereo or metadata matters, convert AAC to M4A or AAC to MP3 instead.

Should I choose AMR Narrow Band or AMR Wide Band?

Pick AMR Narrow Band (8 kHz, 4.75–12.2 kbps) for the broadest compatibility with older phones, MMS, and 2G/3G voicemail — it is the default. Pick AMR Wide Band (G.722.2, 6.60–23.85 kbps) when the receiving device supports HD Voice and you want clearer speech; AMR-WB at 12.65 kbps usually sounds noticeably better than AMR-NB at 12.2 kbps. Both are mono and both are built for voice, not music.

Why does my AAC-to-AMR output sound thin, muffled, or robotic?

That is AMR working as designed. Its ACELP codec models the human vocal tract with very few bits per frame, so it keeps only speech frequencies and, at the lowest modes, can make consonants warble. If the source was music it will always sound hollow through AMR. For spoken-word audio, stepping up to 7.40 or 12.2 KBPS AMR-NB (or an AMR-WB mode) keeps it clean.

In your testing, how small does a one-minute AAC clip get as AMR?

In our testing, a one-minute AAC voice clip re-encoded 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 an equally tiny file, but the result was 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.