AAC to OPUS Converter
Convert AAC to OPUS locally in your browser, powered by Mediabunny and native WebCodecs — nothing is ever uploaded. Drop a AAC file below to get started.
Drop files, or click to browse
AAC files only — processed one at a time
Frequently asked questions
Is this AAC to OPUS converter free?+
Yes, with no watermark, no account, and no daily limit.
Is my audio file uploaded anywhere?+
No — conversion runs locally using your browser's own built-in media codecs, entirely inside your browser tab.
Will I lose audio quality?+
Converting between compressed formats can lose a small amount of quality; converting to a lossless format like WAV or FLAC won't.
Is there a maximum file size?+
There's no fixed file-size limit since nothing is uploaded to a server. Processing time scales with the track's length rather than a hard cutoff.
How do I convert AAC to OPUS?+
Drop your AAC file into the box above — it's decoded and re-encoded as OPUS automatically, with a download ready in seconds.
About AAC and OPUS
What is AAC?
AAC is the compressed audio format behind iTunes, YouTube, and most streaming services — generally more efficient than MP3 at the same bitrate.
Full AAC format guide →What is OPUS?
Opus is a modern, royalty-free codec built for both music and speech, widely used in video calls and voice messaging.
Full OPUS format guide →The short version: OPUS gives you excellent quality at low bitrates, which helps once you run into AAC's biggest limitation: slightly less universal hardware support than MP3, though still very broad. It's a natural move when your audio is headed toward voice and video calls.
How it works
- 1
Drop your file in
Drag your audio onto the box above, or click it to browse — there's no account to create and no upload to wait on.
- 2
Pick your settings
The output format is already set for this page — just adjust any extra options shown, if there are any.
- 3
Download the result
Your browser processes everything locally and hands you a download link the moment it's done — nothing was ever sent to a server.
Is it private?
Everything happens locally, inside this browser tab. Your audio is read from disk, processed with WebAssembly running on your own device, and handed back to you as a download — it's never transmitted anywhere, so there's nothing to intercept and nothing stored on a server.
Common use cases
- Voice and video calls
- Streaming at low bandwidth
- Prepping a podcast episode for a hosting platform
- Fitting a voice memo under a messaging app's size limit
Supported formats
This is one of many pairings the audio toolkit handles. In total it covers:
Related conversions
Format details
About AAC files+
AAC is the compressed audio format behind iTunes, YouTube, and most streaming services — generally more efficient than MP3 at the same bitrate.
AAC (Advanced Audio Coding) was developed as the designated successor to MP3 under the MPEG standard, using newer compression techniques to squeeze out noticeably better sound quality at the same bitrate, or an equivalent quality at a smaller file size. Apple adopted it as the default format across iTunes and the iPhone early on, and it's since become the standard codec behind most video and streaming platforms as well, since it handles the low bitrates needed for streaming particularly well.
How to open a AAC file
Opens readily in Any modern media player, Any web browser, iTunes/Apple Music. For real editing, use Audacity (free), Adobe Audition.
Good for
- better quality-per-kilobit than MP3
- the default format across Apple's ecosystem
Watch out for
- slightly less universal hardware support than MP3, though still very broad
About OPUS files+
Opus is a modern, royalty-free codec built for both music and speech, widely used in video calls and voice messaging.
Opus was developed by the IETF and the Xiph.Org Foundation to unify what used to be two separate problems — speech codecs and music codecs — into a single format that performs well at both, with very low latency. That low latency and strong quality at low bitrates is exactly why it's become the default codec behind most modern video and voice calling: WhatsApp, Discord, Google Meet, and many others all rely on it under the hood, even when users never see the format name at all.
How to open a OPUS file
Opens readily in VLC Media Player, Most modern browsers and media players. For real editing, use Audacity (with recent versions).
Good for
- excellent quality at low bitrates
- low latency, ideal for real-time audio
Watch out for
- less common as a general music-library format
Need a different format? Try the full Audio Converter, or explore all audio tools.