How to convert AAC to Opus
- 1
Upload your file
Drag and drop a file or click to select one. Keep this page open while the file uploads and converts.
- 2
Convert AAC to Opus
NexMedia converts AAC to Opus on its own servers. Processing time depends on the file size and how busy the queue is.
- 3
Download the converted file
When the conversion finishes, the download appears on this page. Your converted file is kept for 2 hours, then deleted.
About AAC
AAC (Advanced Audio Coding) is the lossy audio codec standardised in MPEG-2 and MPEG-4 as the successor to MP3; at the same bitrate it generally sounds better than MP3.
It is the audio in most MP4 videos, in Apple Music and on YouTube; a .aac file is a bare AAC stream without a container.
A bare .aac stream has only limited room for tags and cover art, so music players usually expect AAC inside an M4A file.
Convert AAC to Opus online free, no account required — Opus is a modern open lossy codec for speech and music.
Change AAC to Opus without losing quality — convert AAC to Opus free in your browser.
Why won't my old MP3 player or car stereo play AAC files? Older hardware was built before AAC became common and often only decodes MP3, so a conversion keeps the music playable anywhere.
About Opus
Opus is an open, royalty-free lossy audio codec standardised by the IETF in 2012 (RFC 6716). It handles both speech and music well, from very low to high bitrates.
Voice and video calls, WhatsApp voice messages, WebRTC, and the audio track of WebM videos.
Opus always decodes at 48 kHz, and some older players and devices do not support it.
Why convert voice recordings to Opus? It stays clear at very low bitrates, so calls and dictation shrink dramatically without becoming hard to understand.
What changes when you convert AAC to Opus
- The audio is decoded and re-encoded as Opus at the default settings, so the result is close to the AAC but not bit-identical.
- AAC and Opus are both lossy formats, so this conversion adds a second round of lossy compression; keep the original AAC if you may need the best quality later.
Settings you can change
Before you convert AAC to Opus, you can adjust: Audio codec, Rate control, Audio bitrate, Quality (VBR), Sample rate, Channels, Normalize loudness, Trim start, Trim duration, and Keep tags.
Limits
Each plan sets a maximum file size and a number of conversions per day, and video and audio files also have a maximum length. Guests can convert files up to 100 megabytes and 5 per day; a free account raises this to 500 megabytes and 25 per day; paid plans go up to 100 gigabytes.
Your converted Opus file is kept for 2 hours, then deleted.
AAC to Opus: questions and answers
Does converting AAC to Opus reduce quality?
The audio is decoded and re-encoded as Opus at the default settings, so the result is close to the AAC but not bit-identical. AAC and Opus are both lossy formats, so this conversion adds a second round of lossy compression; keep the original AAC if you may need the best quality later.
What is the difference between AAC and Opus?
AAC is the lossy audio codec that succeeded MP3. Opus is a modern open lossy codec for speech and music.
Can I change the settings when converting AAC to Opus?
Before you convert AAC to Opus, you can adjust: Audio codec, Rate control, Audio bitrate, Quality (VBR), Sample rate, Channels, Normalize loudness, Trim start, Trim duration, and Keep tags.
Do I need an account to convert AAC to Opus?
No. You can convert AAC to Opus without an account; signing in raises the file-size and daily limits.
How long is my converted Opus file kept?
The Opus file you convert from AAC is kept for 2 hours, then deleted automatically.
My AAC is already lossy — does the Opus lose even more?
AAC and Opus are both lossy formats, so this conversion adds a second round of lossy compression; keep the original AAC if you may need the best quality later.
When I convert AAC to Opus, is the audio re-encoded?
The audio is decoded and re-encoded as Opus at the default settings, so the result is close to the AAC but not bit-identical.