How do I convert AMR to AAC?

Add your AMR file to the upload area above, then press Convert. The AAC file downloads straight to your device. You do not need an account, and there is no watermark.

Are my files uploaded to a server?

No. This conversion runs entirely inside your browser using WebAssembly, so the file never leaves your device — you can even disconnect from the internet after the page loads and it will still work.

Does converting to AAC reduce quality?

AAC uses lossy compression, so some data is discarded. At the default quality the difference is very hard to see or hear; raise the quality setting if you need to be certain, at the cost of a larger file.

How large a file can I convert?

Up to 300 MB per file for this conversion. Because the work happens in your browser, the practical limit is your device's memory — larger files work on a desktop with plenty of RAM and may fail on an older phone.

Can I convert several files at once?

Yes. Add as many as you like and press Convert All. Each file is processed independently, so one failure does not stop the rest, and you can download everything together as a ZIP.

Can I use this on my phone?

Yes. FileTools360 works in mobile browsers on iOS and Android, including choosing files straight from your camera roll. Very large videos may run out of memory on a phone — those are better converted on a laptop.

AudioAdjustable qualityRuns in your browser

AMR to AAC Converter

Turn AMR files into AAC in a couple of clicks. Narrowband speech codec from mobile voice recordings. The successor to MP3 — better quality per bit. The output is re-encoded, so quality depends on the settings you choose.

On your deviceNever uploadedGone when you close the tabHow this works

Drop your files here

AMR files (.amr) · up to 300 MB each

or paste files from your clipboard

Ready when you are

Drop a AMR file above and FileTools360 will turn it into AAC — right here on your device, without uploading anything.

⌘K to search converters

How to use it

1
Add your AMR files
Drag them onto the upload area, choose them from your device, or paste them from your clipboard. You can queue several at once.
2
Adjust the settings if you want to
The defaults suit most people. Open Advanced to control bitrate, sample rate and channels and start and end times.
3
Convert and download
Press Convert. Everything happens on your own device — nothing is uploaded. Download files one by one, or grab them all as a ZIP.

AMR and AAC explained

AMR is a narrowband speech codec designed for mobile phone calls. It is optimised specifically for the frequency range of the human voice and sounds poor for anything else.

AAC is the successor to MP3 and is the default audio codec for MP4 video, Apple Music and YouTube. At the same bitrate it generally sounds noticeably better than MP3.

Where AMR files come from: Voice memos and voicemail from older phones.
Where AAC is used: Streaming services, video soundtracks and Apple devices.

AMR vs AAC

The two formats solve different problems, which is why converting between them involves trade-offs rather than a straight upgrade.

AMR compared with AAC
Property	Source	Target
Compression	Lossy	Lossy
Introduced	1999	1997
Browser support	Poor. Convert to MP3 or WAV to use it.	Excellent across modern devices.

AMR is stronger at: Extremely small files. Adequate for speech intelligibility.
AAC is stronger at: Better quality per bit than MP3. The standard audio track for MP4 video. Excellent device support.

Why convert AMR to AAC?

People make this switch when they run into the limits of AMR: always — convert to MP3 or WAV so the recording stays usable. AAC is the better fit when modern streaming, or the audio track of a video.

AMR limitations that prompt the switch: Terrible for music. Very limited playback support. Low sample rate ceiling.
What you give up: Still lossy. Patent licensing applies to encoders.

Does converting AMR to AAC reduce quality?

Both AMR and AAC are lossy, so this is a re-encode: the file is decoded and compressed again. At the default quality setting the difference is very hard to see, but each successive re-encode compounds. If you will need the file again later, keep the AMR original rather than converting back and forth.