MP4 to OPUS Converter
Initializing... drag & drop files here
Supports: MP4, M4V
Advanced Options - Our defaults are optimized for the best results. We recommend you keeping the defaults unless you have a specific need.
Reset to defaults
Need help?Convert MP4 to Opus Online
Pull the audio out of an MP4 video and re-encode it as Opus — the codec that beats MP3 and AAC at low bitrates, so a podcast, lecture, or voice clip ends up far smaller at the same listenable quality. Opus is the native audio codec behind Discord, WhatsApp, and Zoom, which makes it the natural choice when you only need the sound and want the file as light as possible.
How to Convert MP4 to Opus
- Upload Your MP4 File: Drag and drop or click "+ Add Files" to add an MP4 or M4V. The audio track is extracted; the video is discarded.
- Pick a Quality Preset: Open Advanced Options and choose a Quality Preset (Highest down to Lowest). For finer control, switch to Variable Bitrate (Opus ranges from 6k–24k for speech up to 256k–320k for music) or set a Custom Bitrate.
- Adjust Audio Channel or Trim (Optional): Force mono with Audio Channel to roughly halve the size of a voice recording, change Audio Sample Rate, or use Trim to keep only the part you need.
- Convert and Download: Click "Convert" and download your .opus file. No sign-up, no watermark.
Opus vs MP3 vs AAC — Which Bitrate to Use
| Use case | Recommended codec | Opus bitrate | Why |
|---|---|---|---|
| Voice / podcast / lecture | Opus | 24–48 kbps | Speech stays clear where MP3/AAC sound rough |
| Music, balanced size | Opus | 96–128 kbps | ~96 kbps Opus edges out AAC and clearly beats MP3 |
| Archival / near-transparent | Opus | 160–256 kbps | Diminishing returns above this; 510 kbps is the ceiling |
| Maximum device compatibility | MP3 instead | 128–192 kbps | Plays everywhere; use MP4 to MP3 if a target lacks Opus support |
Frequently Asked Questions
Why is Opus smaller than MP3 at the same quality?
Opus uses a more modern hybrid design (SILK for speech, CELT for music) standardized by the IETF as RFC 6716. In listening tests it delivers superior quality to HE-AAC around 64 kbps and slightly beats AAC — while clearly outperforming MP3 — around 96 kbps. That means you can drop the bitrate (and the file size) well below what MP3 needs and still keep the audio clear, which is why SoundCloud and YouTube adopted it.
What plays .opus files?
Opus plays natively in Chrome, Firefox, Edge, and Safari, in VLC, and in apps like Foobar2000. On phones it is built into Android and supported on iOS 11+. If a device or editor refuses it, convert to MP4 to MP3 instead — MP3 is the most universally playable fallback.
What bitrate should I use to fit Discord's upload limit?
Discord's free tier caps uploads at 10 MB per file, Nitro Basic at 50 MB, and Nitro at 500 MB. Extracting audio alone already shrinks an MP4 dramatically; at 96 kbps Opus, roughly an hour of audio fits inside 10 MB. For voice clips, choose a Quality Preset in the Low–Medium range or set Variable Bitrate to 24k–48k to stay comfortably under the cap. The same math works for Gmail's 25 MB attachment limit.
Does converting MP4 to Opus re-compress the audio?
Yes. MP4 audio is usually AAC, and Opus is a different codec, so this is a re-encode (lossy to lossy), not a passthrough. Pick a bitrate at or above the source — for example 128 kbps Opus from a 128 kbps AAC track — to keep the generation loss inaudible. There is no way to get back detail the original AAC already discarded.
How small will the Opus file actually be?
In our testing, a 60-second 1080p MP4 with a stereo AAC soundtrack, extracted at the Variable Bitrate 96k–128k setting, produced an Opus file of about 0.7–0.9 MB — a fraction of the source video, since the picture is dropped entirely. Forcing mono with Audio Channel roughly halves that again for spoken-word recordings. To squeeze an existing file further, run it through the Audio Compressor.