How to convert Opus to M4A (AAC/ALAC)
- 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 Opus to M4A (AAC/ALAC)
NexMedia converts Opus to M4A (AAC/ALAC) 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 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.
Convert Opus to M4A online free, no account required — M4A is an MPEG-4 audio file, usually holding AAC.
Change Opus to M4A without losing quality — convert Opus to M4A free in your browser.
Why won't my car stereo or older phone play Opus files? The codec only became widespread in the last decade, and hardware that predates it usually decodes just MP3 — converting keeps the music compatible.
About M4A (AAC/ALAC)
M4A is an MPEG-4 audio file: the MP4 container holding only audio, usually AAC and sometimes Apple Lossless (ALAC).
Music bought on iTunes, iPhone voice memos and many podcast downloads.
Whether an M4A is lossy or lossless depends on the codec inside, which the file extension does not show.
Why convert audio to M4A? It wraps efficient AAC audio with chapter marks and cover art in one small file that Apple, Android and Windows all play.
What changes when you convert Opus to M4A
- The audio is decoded and re-encoded as M4A at the default settings, so the result is close to the Opus but not bit-identical.
Settings you can change
Before you convert Opus to M4A, 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 M4A file is kept for 2 hours, then deleted.
Opus to M4A: questions and answers
Does converting Opus to M4A reduce quality?
The audio is decoded and re-encoded as M4A at the default settings, so the result is close to the Opus but not bit-identical.
What is the difference between Opus and M4A?
Opus is a modern open lossy codec for speech and music. M4A is an MPEG-4 audio file, usually holding AAC.
Can I change the settings when converting Opus to M4A?
Before you convert Opus to M4A, 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 Opus to M4A?
No. You can convert Opus to M4A without an account; signing in raises the file-size and daily limits.
How long is my converted M4A file kept?
The M4A file you convert from Opus is kept for 2 hours, then deleted automatically.
When I convert Opus to M4A, is the audio re-encoded?
The audio is decoded and re-encoded as M4A at the default settings, so the result is close to the Opus but not bit-identical.
Will converting Opus to M4A change my original file?
No. The conversion reads your Opus and writes a new M4A file, leaving your original Opus file untouched.