AMR to CAF Converter
FileFlip converts AMR to CAF entirely inside your browser, using FFmpeg compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert an AMR file to CAF?#
- Drop your AMR file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to CAF and the conversion starts on its own. FileFlip downloads 30.8 MB of WebAssembly the first time and nothing after that, then runs FFmpeg on your own machine.
- Save the CAF file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting AMR to CAF lose quality?#
It depends on what is inside the file. AMR is a container rather than a codec, so whether the CAF conversion copies the streams across untouched or re-encodes them is decided by the codecs that particular file happens to use.
Is it safe to convert AMR files online?#
Yes, because nothing is uploaded. FileFlip converts AMR files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What AMR to CAF actually does to the file#
Converting AMR to CAF runs on FFmpeg, downloads 30.8 MB of WebAssembly the first time and nothing after that, re-encodes or copies through depending on the codecs in the file, and drops encoded streams.
| Engine | FFmpeg |
|---|---|
| Conversion path | One step: AMR → CAF |
| Downloaded to your browser | 30.8 MB, once, then cached by your browser |
| Quality | Decided by the codecs inside the file |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Encoded streams | Dropped | The target format has nowhere to put it. |
What is an AMR file?#
An AMR file holds speech compressed with Adaptive Multi-Rate, the narrowband codec 3GPP standardized in 1999 for GSM phone calls, which is why voice memos and MMS voice messages recorded on older phones end up in this format.
There is rarely a reason to keep audio as AMR once it is off the phone that made it, since the format exists for the transmission link, not for storage.
Convert AMR to MP3 or WAV so an old voice memo or MMS recording opens in ordinary media players and editing software, keeping in mind the recording will still sound like a phone call because that ceiling was set at capture, not by the format.
What is a CAF file?#
A CAF file holds audio in Apple's Core Audio Format, introduced in 2005 to replace AIFF and WAV on the Mac because its 64-bit chunk sizes have no practical file size or duration limit.
Keep audio as CAF while it stays inside Apple's own tools, such as Logic Pro, GarageBand, or an iOS app's own audio recordings, where the format's size and codec flexibility are used directly.
Convert CAF to WAV or M4A when the audio needs to leave the Apple ecosystem, since most non-Apple software has no built-in way to open it.
AMR to CAF questions people ask#
Why are my voice memos and MMS recordings AMR files?
AMR is the speech codec GSM and 3G phones use for voice calls, so many phones' voice recorder apps and MMS voice messages reused the same codec rather than encoding a separate format. That link to phone-call audio is also why AMR recordings sound like a phone call, thin and narrowband, rather than like a full-range voice recording.
What plays AMR files?
VLC plays AMR files on every major platform, and Android's own voice recorder and messaging apps read them natively since AMR originated on that ecosystem. Standard desktop media players such as Windows Media Player or QuickTime generally do not.
What should I convert AMR to?
Convert AMR to MP3 or WAV so the recording opens in any media player or editor. Converting will not improve the sound, since AMR only ever captured the narrow speech frequency range a phone call uses, and no conversion can add back detail the codec discarded at recording time.
What creates a CAF file?
CAF files come from Apple's own audio software, including Logic Pro, GarageBand, and any iOS or macOS app that records audio through Apple's Core Audio APIs. Apple adopted CAF as its own format specifically to avoid the 4 GB size limit that WAV and AIFF both carry.