Convert AAC to OPUS
Turn an AAC file into OPUS, the efficient format behind Discord, WhatsApp voice notes and a lot of web streaming. The conversion runs in your browser.
Why convert AAC to OPUS?
OPUS is exceptionally efficient, especially for speech, which is why it powers Discord audio, WhatsApp and Telegram voice notes, and much of web streaming. It gives you very small files that still sound good. Convert when you want to share audio in a messaging app, upload to a platform that prefers OPUS, or save space on a large collection of spoken-word recordings.
Quality and file size
Both formats are lossy, so this is a transcode that adds a small amount of loss on top of the AAC encode. OPUS is highly efficient and sounds very good at modest bitrates, particularly for voice. The OPUS encoder tops out at 256 kbps, so choosing the highest quality setting produces a 256 kbps file. For music, 192 to 256 kbps is transparent for most listeners. OPUS cannot restore detail the AAC already removed.
AAC to OPUS: common questions
Why is the highest OPUS quality 256 kbps?
The OPUS encoder does not accept bitrates above 256 kbps, so the top setting is capped there. OPUS is efficient enough that 256 kbps is already transparent for music for most listeners.
Is my file uploaded anywhere?
No. The conversion runs entirely in your browser with FFmpeg compiled to WebAssembly. Your file never leaves your device, and we never see it, store it, or train on it.
Is OPUS good for music or just voice?
Both. It is famous for voice because it sounds good at very low bitrates, but at 192 to 256 kbps it handles music very well too. For voice notes, even 64 kbps sounds clear.
Will converting to OPUS reduce quality?
Slightly, since it re-encodes lossy audio. For speech it is not noticeable, and for music at 192 kbps or higher most people will not hear a difference.
Who makes this?
We're the small team behind Xport Studio, a private, fully offline app for AI vocals, stems, and mastering. These free tools are side experiments we wanted to share. No upsell, but if you're curious about the bigger thing, take a look.