How to convert MP4 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 MP4 to Opus
NexMedia converts MP4 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 MP4
MP4 (MPEG-4 Part 14) is a container format standardised by ISO. It usually holds H.264 or H.265 video with AAC audio, and it can also carry subtitles and chapter markers.
It is the most widely supported video format: phones, browsers, smart TVs and video sites all play it.
The video inside an MP4 is almost always compressed with a lossy codec, so every re-encode loses a little quality.
Convert MP4 to Opus online free, no account required — Opus is a modern open lossy codec for speech and music.
Change MP4 to Opus without losing quality — convert MP4 to Opus free in your browser.
Why is my MP4 file so large? MP4 video is already compressed with H.264 or H.265, so a lower bitrate or resolution shrinks the file at the cost of some quality.
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 MP4 to Opus
- The soundtrack of the MP4 is re-encoded as Opus at the default settings, so it is close to the original but not bit-identical.
- Only the sound is kept: the Opus file contains the audio track of your MP4, and the picture is dropped.
Settings you can change
Before you convert MP4 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.
MP4 to Opus: questions and answers
Does converting MP4 to Opus reduce quality?
The soundtrack of the MP4 is re-encoded as Opus at the default settings, so it is close to the original but not bit-identical.
What is the difference between MP4 and Opus?
MP4 is a widely supported video container, usually holding H.264 video and AAC audio. Opus is a modern open lossy codec for speech and music.
Can I change the settings when converting MP4 to Opus?
Before you convert MP4 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 MP4 to Opus?
No. You can convert MP4 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 MP4 is kept for 2 hours, then deleted automatically.
When I convert MP4 to Opus, can I keep just the sound?
Only the sound is kept: the Opus file contains the audio track of your MP4, and the picture is dropped.
Will converting MP4 to Opus change my original file?
No. The conversion reads your MP4 and writes a new Opus file, leaving your original MP4 file untouched.