Free tool
Opus to MP3 converter
Drop an .opus file here to turn Opus to MP3 in your browser: a WhatsApp voice note or any other Opus recording comes out as an MP3 at 128, 192 or 320 kbps, ready for the players and apps that won’t open .opus.
- Free
- Reads .opus as it is
- Nothing is uploaded
Save as
MP3 quality
Plays everywhere. The sound is re-encoded at the quality you pick.
Drop your Opus file here, or Choose your Opus file
Any audio or video file, up to 1 GB and 2 hours. It’s converted in your browser; nothing is uploaded.
MP3 encoding by LAME, open-source software.
Keeping voice notes for what was said in them? Convert them here, and NoteOwl imports the MP3s on your Mac and turns them into text you can search.
How it works
How do you convert an .opus file?
Drop the .opus file with MP3 chosen. The page reads the Ogg wrapper around the sound, your browser’s own decoder turns the Opus back into samples at 48 kHz, and the MP3 encoder inside the page writes them out. A one-minute voice note took half a second in Chrome.
- 1
Choose the MP3 quality
128 kbps covers a voice note. Pick 192 or 320 kbps when the Opus file is music.
- 2
Add the .opus file
Copied from a phone, downloaded, or anywhere on your computer. There is no need to rename it first.
- 3
Save the MP3
Play it in the page, then download it. The MP3 carries the .opus file’s name.
What size MP3 does an Opus file make?
An MP3’s size depends only on its bitrate and length: 0.96 MB a minute at 128 kbps, 1.44 MB at 192. So a five-minute stereo Opus file of 2.83 MB, recorded at 96 kbps, became 4.8 MB at 128 kbps and 7.2 MB at 192 kbps.
- 1 min, mono voice note
- MP3 out128 kbps, 48 kHz mono
- Size0.96 MB
- Took (Chrome / WebKit)0.5 s / 0.7 s
- 5 min, stereo, 96 kbps, 2.83 MB
- MP3 out128 kbps, 48 kHz stereo
- Size4.8 MB
- Took (Chrome / WebKit)3.6 s / 3.9 s
- The same 5 min file
- MP3 out192 kbps, 48 kHz stereo
- Size7.2 MB
- Took (Chrome / WebKit)3.2 s / 3.8 s
| .opus file in | MP3 out | Size | Took (Chrome / WebKit) |
|---|---|---|---|
| 1 min, mono voice note | 128 kbps, 48 kHz mono | 0.96 MB | 0.5 s / 0.7 s |
| 5 min, stereo, 96 kbps, 2.83 MB | 128 kbps, 48 kHz stereo | 4.8 MB | 3.6 s / 3.9 s |
| The same 5 min file | 192 kbps, 48 kHz stereo | 7.2 MB | 3.2 s / 3.8 s |
What is inside a file that ends in .opus?
Opus sound in an Ogg container. The .opus ending marks an Ogg file that holds only Opus audio, the same kind of file as an Opus .ogg under a clearer name. Opus itself is an open, royalty-free codec, standardised in 2012 for both speech and music.
It was built to stay clear at low bitrates: chat apps use it for voice notes, and browsers for calls. Video sites such as YouTube stream much of their sound in Opus too, so audio downloaded from them often ends in .opus.
- Standard
- OpusIETF RFC 6716 (2012)
- Bitrates
- Opus6 to 510 kbps
- Decoded at
- Opus48 kHz, whatever the recording’s rate
- In a .opus file
- OpusOgg container (RFC 7845)
- Where you meet it
- OpusWhatsApp and Telegram voice messages, browser calls, video sites
| Opus | |
|---|---|
| Standard | IETF RFC 6716 (2012) |
| Bitrates | 6 to 510 kbps |
| Decoded at | 48 kHz, whatever the recording’s rate |
| In a .opus file | Ogg container (RFC 7845) |
| Where you meet it | WhatsApp and Telegram voice messages, browser calls, video sites |
Where does WhatsApp keep .opus voice notes on Android?
In the phone’s storage under Android › media › com.whatsapp › WhatsApp › Media › WhatsApp Voice Notes, sorted into folders by date. Each opus file is named PTT followed by the date, such as PTT-20261016-WA0002.opus. Copy them to a computer with a USB cable, or open this page on the phone.
Why convert an Opus file when it is already so small?
Because plenty of software still won’t open .opus. Many car stereos and older music players, a good few audio and video editors, and many upload forms take MP3 but not .opus. The MP3 costs more space, 4.8 MB where the Opus file took 2.83 MB, but it plays almost everywhere.
Why does the MP3 come out at 48 kHz?
Because Opus is decoded at 48 kHz, whatever rate the voice was recorded at, and the converter keeps the rate it is handed. Untick Keep the original sample rate for a 44.1 kHz MP3 if the place you are sending it asks for that rate.
Can a WhatsApp voice note become a searchable note on a Mac?
Yes. NoteOwl imports the MP3 you make here and transcribes it on your Mac with on-device AI models, so a voice note or a recorded call becomes text you can search later. Dictation into any app is free.
For a quick transcript of the .opus file itself, without converting, try Opus to text in the browser.
FAQ
Opus to MP3: what people ask
Is my .opus file sent anywhere when I convert it?
No. It is read and decoded by your own browser, and the MP3 is encoded inside the page. Nothing is uploaded, so a private voice note stays on your phone or computer.
Is an .opus file the same as an .ogg file?
Nearly. Both are Ogg files, and the .opus ending says the sound inside is Opus, while an .ogg can hold Opus or the older Vorbis. The converter looks at the contents, so either ending converts the same way.
Which MP3 bitrate suits a voice note?
128 kbps, which takes about 0.96 MB a minute. Keep 192 kbps (1.44 MB a minute) and 320 kbps (2.4 MB a minute) for Opus files that hold music.
Why won’t my .opus file play on my computer?
Many players and some built-in apps have no Opus decoder for .opus files. Chrome, Firefox and VLC play them; turned into an MP3, the voice note plays in nearly everything else.
How fast is the conversion?
A one-minute voice note took 0.5 seconds in Chrome and 0.7 seconds in Safari’s engine on an Apple M1 Pro. A five-minute stereo Opus file took between 3.2 and 3.9 seconds.
What is the Opus codec used for?
Mostly for voices: WhatsApp and Telegram voice messages and calls made in a browser all use it. It carries music on video sites as well, since it was designed for both speech and music at bitrates from 6 to 510 kbps.
How long an Opus recording can it convert?
Up to 2 hours or 1 GB per file. Opus files are small, so length is the limit you will meet first: two hours as a 128 kbps MP3 comes to about 115 MB.
Keep exploring
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- MP3 converterConvert any audio or video file to MP3 in your browser, from WAV, M4A, FLAC, OGG and AIFF to MP4, MOV and WebM videos; nothing is uploaded
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Related
- OGG to MP3 converterConvert OGG files to MP3 in your browser, Opus voice messages and Vorbis music alike; nothing is uploaded
- Opus to textTurn a Opus file into text free in your browser: AI transcription with times, as text, SRT, VTT or Word; nothing is stored
- Voice notes on your MacVoice notes and dictations saved as searchable text on your Mac, with the raw words beside the polished version; free
Voice notes into text you can search, on your Mac
Free to download. Runs entirely on your Mac.
macOS 26 or later · Apple Silicon (M1 or newer) · 16 GB memory minimum, 24 GB recommended
About NoteOwl
NoteOwl is private AI meeting notes and memory for the Mac. It captures meetings without a bot joining the call, labels every speaker, writes summaries and action items, and builds a memory of every conversation that you can chat with — fully offline, because the speech recognition and the AI run on the Mac itself. Dictation into any app is free; Pro is a one-time purchase.
NoteOwl pricing: what’s free and what Pro adds
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