Turn AMR files into AAC
This makes an AAC out of the AMR you already have. AAC is the usual choice for audio tracks inside MP4 video. The practical difference is that the result opens anywhere, which AMR files do not. Your file never leaves your computer.
How to convert AMR to AAC
- 1 Drop your AMR .amr file onto the page, or click to browse for it.
- 2 Set the quality, or leave the default, which keeps the file small without anything showing.
- 3 Convert. The work happens on your own machine, so how long it takes depends on your computer and the file.
- 4 Download the AAC, or add more files and do the whole set in one go.
Why convert AMR to AAC
- An AMR will not open in a browser, so anything going onto a web page, into a document or into a message has to become an AAC first.
- Better quality than MP3 at any comparable file size.
- Plays everywhere without draining the battery.
- Audio tracks inside MP4 video.
- AMR: almost no consumer software plays it directly.
AMR compared with AAC
How the two formats differ on the things that decide whether a conversion is worth making.
| Property | AMR | AAC |
|---|---|---|
| File extension | .amr | .aac |
| Browser support | No browser support | Every browser |
| Introduced | 1999 | 1997 |
| Developed by | 3GPP | ISO/IEC MPEG |
Quality and what changes
Both formats are lossy, so this is a second generation of compression: the AMR is decoded back to pixels that already carry its artefacts, and AAC then compresses that. The damage compounds rather than cancelling out, which is why repeated round trips visibly degrade an image. Encode at a higher quality than the source used, and convert once from the best copy you have rather than from an already converted file.
- AMR files can be read here but not created, so conversions run one way only.
- One AAC limitation to keep in mind: patent licensing applies to encoders in commercial products.
Questions about AMR to AAC
Will converting AMR to AAC lose quality?
A little. Both formats are lossy, so the file is decoded and compressed a second time and the two sets of artefacts add up. At a high quality setting the difference is hard to see, but avoid repeated round trips between lossy formats.
Is my AMR file uploaded anywhere?
No. The whole thing runs inside the browser tab you already have open. Your AMR is read straight from your own disk, converted on your machine and handed back as an AAC. Nothing is sent anywhere, nothing is stored and there is no account.
Is there a file size limit?
There is no server-side limit because no server sees the file. The real ceiling is your device memory, since the input and the output both have to fit in the tab. A few hundred megabytes is usually fine on a desktop machine and considerably less on a phone.
Can I convert several AMR files at once?
Yes. Add as many as you like and they are processed one after another, then offered as separate AAC downloads or as a single ZIP. Speed depends on your own processor rather than on a queue.
Does the converter work offline?
Yes, after the page has loaded once. The engine is cached by the browser, so you can disconnect, reload and keep converting. That falls out of doing the work locally rather than being a separate mode you switch on.