How do I convert Opus to AAC?

Add your Opus 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

Opus to AAC Converter

Turn Opus files into AAC in a couple of clicks. The best low-bitrate codec available — voice and music. 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

Opus files (.opus) · up to 300 MB each

or paste files from your clipboard

Ready when you are

Drop a Opus 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 Opus 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.

Opus and AAC explained

Opus is the current state of the art for lossy audio, and the codec behind most voice calls you make over the internet. It performs well across an unusually wide range, from 6 kbps speech to transparent music.

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 Opus files come from: Voice and video calls, modern podcast pipelines and WebRTC.
Where AAC is used: Streaming services, video soundtracks and Apple devices.

Opus vs AAC

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

Opus compared with AAC
Property	Source	Target
Compression	Lossy	Lossy
Introduced	2012	1997
Browser support	Modern browsers and apps; older hardware may not.	Excellent across modern devices.

Opus is stronger at: Best-in-class quality at low bitrates. Extremely low latency, which is why calls use it. Royalty-free.
AAC is stronger at: Better quality per bit than MP3. The standard audio track for MP4 video. Excellent device support.

Why convert Opus to AAC?

People make this switch when they run into the limits of Opus: playback on older or embedded hardware. AAC is the better fit when modern streaming, or the audio track of a video.

Opus limitations that prompt the switch: Older hardware and car stereos generally cannot play it. Less recognised by users than MP3.
What you give up: Still lossy. Patent licensing applies to encoders.

Does converting Opus to AAC reduce quality?

Both Opus 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 Opus original rather than converting back and forth.