AMR to M4R Converter

How to Convert AMR to M4R Online

1. Upload Your AMR File: Drag and drop the .amr recording onto the page or click "+ Add Files". Voice recordings from older phones, call-recorder exports, voicemail downloads and MMS audio clips all work, and a batch of short recordings can be converted together.
2. Trim to the Words You Want: Open Trim, set the Start time just before the line you want and a Duration of 30 seconds or less, in seconds or HH:MM:SS.sss. The note under Duration repeats Apple's 30-second guidance for iPhone ringtones. Cutting off silence at the start makes the tone ring straight away.
3. Keep It Mono and Modest: Set Audio Channel to Mono and leave Audio Sample Rate on Original. Under File Compression, a Constant Bitrate of 32-64 kbps is plenty for AMR speech; the range runs from 8 to 384 kbps. Variable Bitrate offers five AAC bands from 20k-32k up to 96k-112k, and Custom Bitrate, Specific file size and the hands-off Quality Preset are also available.
4. Convert and Download: Click "Convert" and save the .m4r. The recording is uploaded over HTTPS, encoded on our servers and deleted automatically after a few hours. No sign-up, no watermark.

AMR: Phone-Call Audio in a File

AMR (Adaptive Multi-Rate) is a speech codec from the mobile-phone world, standardised by 3GPP for GSM and 3G voice calls. Phones also used it to store audio, which is why .amr files come from:

• Voice recorders on older phones. Many feature phones and early Android phones saved voice memos as .amr to keep them small.
• Call recorders and voicemail. Plenty of call-recording apps and voicemail exports use AMR, since it is the codec the call itself used.
• MMS messages. Audio clips attached to picture messages were frequently AMR.

The narrowband variant (AMR-NB) samples at 8 kHz and runs at one of eight bitrates between 4.75 and 12.2 kbps; the wideband variant (AMR-WB) samples at 16 kHz with nine modes from 6.6 to 23.85 kbps. A file starts with the text #!AMR (or #!AMR-WB for wideband), as defined in RFC 4867.

What that means for a ringtone is simple and worth saying plainly: narrowband AMR keeps roughly the telephone band of about 300-3,400 Hz, so your ringtone will sound like a phone call. Voices stay clear and recognisable, but music, bass and cymbals turn thin and watery. That can be exactly the charm, for example a grandparent's "answer the phone!" recorded years ago on a flip phone, or a child's first words saved as a voice memo, assigned to that person in Contacts. Just do not expect a song recorded off a radio into an AMR memo to come out sounding like the song.

An iPhone needs the clip as an .m4r: AAC (AAC-LC) audio in an MPEG-4 container, the same container and codec as an .m4a, with the extension that tells iOS, Finder and iTunes the file is a tone. This page decodes the AMR and encodes it as AAC in one pass. If you want to keep the recording as an ordinary audio file instead, use AMR to M4A. Recordings in other formats are covered from the M4R converter page.

AMR vs M4R: Format Comparison

Narrowband or Wideband: What to Expect and What to Set

Size is bitrate × seconds ÷ 8: 48 kbps × 30 s ÷ 8 = 180 KB. Even the lowest of these rates is several times the AMR's own bitrate, which gives the AAC encoder ample room to reproduce everything the recording contains. Going higher only makes the file larger. Raising the sample rate to 44100 Hz is also possible, but it adds no detail, because the frequencies AMR discarded are gone for good.

Setting the Ringtone on Your iPhone

Get the .m4r onto the phone using one of the usual routes: connect the iPhone to a Mac and drag the file onto the iPhone in the Finder sidebar (macOS Catalina or later), or use iTunes on Windows. Alternatively, save it to Files, import it into GarageBand on the iPhone and use Share > Ringtone, as Apple describes in Create a custom ringtone on your iPhone. Choose it in Settings > Sounds & Haptics > Ringtone (Apple iPhone User Guide). A voice clip is most fun as one person's tone: open their contact, tap Edit, then Ringtone or Text Tone.

Frequently Asked Questions

Why does my ringtone sound like a phone call?

Because the recording is phone-call audio. Narrowband AMR keeps only about 300-3,400 Hz and rebuilds the sound from a speech model at a few kilobits per second. AAC reproduces that faithfully but cannot add back what was never stored, so the tone sounds like the original recording on any phone.

Will a higher bitrate make it sound better?

No. The source carries at most 12.2 kbps of speech information (23.85 kbps for wideband), so 32-64 kbps AAC already captures all of it. Higher rates only produce a bigger file. If anything sounds off, check the trim and the recording itself rather than the bitrate.

How long can the ringtone be?

Apple says iPhone ringtones can be up to 30 seconds long, and GarageBand shortens longer ringtones automatically when exporting; the GarageBand for iPhone User Guide gives 30 seconds as the maximum exported length. A short voice line of a few seconds is fine: it repeats while the phone rings.

Can I use an AMR voicemail as a text tone?

Yes. Apple's GarageBand guide says an exported ringtone can serve as a Standard Ringtone or a Standard Text Tone, and custom tones you add to the iPhone appear in the Text Tone list too. Keep text tones short, a second or two, so they do not talk over each other when several messages arrive.

How do I tell narrowband from wideband?

Open the file in a text or hex viewer and look at the first bytes: #!AMR means narrowband and #!AMR-WB means wideband. ffprobe shows it too, as the codec amr_nb or amr_wb with an 8000 or 16000 Hz sample rate. Some wideband files use the .awb extension instead of .amr.

Is an M4R different from an M4A?

The audio is the same: AAC in an MPEG-4 container. We write M4R with the same MPEG-4 muxer as M4A, and ffprobe reports AAC LC in an MP4 file with major brand M4A . The .m4r extension is what tells iOS the file is a tone. To go the other way, M4R to AMR converts a tone back to AMR.

What about Android phones?

Android does not need M4R; its ringtones are usually MP3 or OGG. AMR to MP3 produces a file any Android phone can use as a ringtone.

Are my voice recordings kept private?

Voicemails and call recordings can be sensitive. Files are uploaded over an encrypted (TLS) connection, converted on our servers and deleted automatically a few hours after processing. They are never shared or made public, and no account is needed. Only make ringtones from recordings that the people in them are comfortable with.