Convert AAC to OPUS online
Free, no sign-up, no limits. Drop your AAC files, get OPUS files back in seconds.
1 files converted so far
Drop your AAC files here
or · multiple files accepted
Local conversion: your files never leave your device.
Why convert AAC to OPUS?
You have a AAC file that will not open on one of your devices or applications. OPUS is more widely supported for your use case: WhatsApp/Telegram voice messages, Discord, calls.
How to do it, step by step
- Drop your AAC fileinto the area at the top of the page (or several files at once). On mobile, tap the area and pick the file from your apps.
- Check the output format: OPUS is already selected. For music, 192 kbps is transparent for most listeners and 320 kbps gives the maximum. For voice (memos, podcasts, lectures), 128 kbps is more than enough and halves the file size.
- Start the conversion.The FFmpeg engine loads once (≈ 10 MB), then each file is processed in a few seconds without leaving your device.
- Download your OPUS, directly or as a .zip if you converted several files. The name and metadata (title, artist, cover art) are preserved.
The AAC format (Advanced Audio Coding)
AAC is the successor to MP3: at the same bitrate, the sound is better. It is the audio codec of YouTube, Apple Music, digital TV and most MP4 videos. A raw .aac file (without the M4A container) is rarer and less well supported than its .m4a equivalent.
- Better quality than MP3 at the same bitrate
- Standard for video and streaming
- Raw .aac file poorly compatible
- No metadata without a container
The OPUS format (Opus Interactive Audio Codec)
Opus is currently the most efficient audio codec: it delivers the best possible quality at very low bitrates. It is the format of WhatsApp, Telegram and Discord voice messages and of video calls. Excellent, but still poorly recognized by consumer players and car stereos.
- Exceptional quality at low bitrates
- Free format
- The standard for voice on the internet
- Very few devices play it
- Often impossible to open on Windows without extra software
AAC vs OPUS comparison
| AAC | OPUS | |
|---|---|---|
| Compression | Lossy | Lossy |
| Typical size (1 min, music) | ≈ 1.2 MB (160k) | ≈ 0.7 MB |
| Common use | streams extracted from videos, digital recorders, streaming | WhatsApp/Telegram voice messages, Discord, calls |
| Metadata (title, cover art) | Limited | Yes |
Frequently asked questions
Does converting AAC to OPUS lose quality?
OPUS is a lossy compressed format: a conversion always involves re-encoding. At 192 kbps or higher, the difference is inaudible in the vast majority of cases. Just avoid chaining several successive conversions.
Is the AAC to OPUS converter free?
Yes, with no limit on the number of files, no sign-up and no watermark. Each file can be up to 200 MB.
Are my AAC files uploaded to the internet?
No. The AAC to OPUS conversion is performed by FFmpeg directly in your browser (WebAssembly). Your files never leave your computer or phone.
How do I convert AAC to OPUS on iPhone or Android?
Open this page in Safari or Chrome, tap the drop area, select your AAC file (from Files, Voice Memos, Downloads or WhatsApp), then tap "Convert". The OPUS downloads to your files.
Can I convert several AAC files at once?
Yes, add all your files in one go. They are converted one after another and a button lets you download everything as a .zip archive.