Convert Opus to MP3
The voice note you were sent, the Discord recording, the podcast download — Opus is what they are, and MP3 is what the car, the old player and the editing app want. Nothing is stored.
- Never stored
- No queue, no waiting
- No signup, no watermark
How it works
Add your Opus file
A .opus file, or an .ogg that holds Opus — voice notes exported from WhatsApp, Telegram and Signal are exactly that. The format is read from the file itself, not its name.
Choose the bitrate
128 kbps is plenty for a single voice, and mono halves the size again. Music recorded in Opus deserves 192 kbps or more.
Download the MP3
One file, named after the original, that plays on everything made since 1995.
What is inside a .opus file
A .opus file is an Ogg container holding Opus audio, the same thing as many .ogg files with a more honest extension. Opus itself is a 2012 IETF standard that merged Skype's SILK speech codec with Xiph's CELT music codec, and it is remarkable at low bitrates: a voice note at 24 kbps is perfectly intelligible, and at 64 kbps stereo music is already hard to tell from the original. It runs at 48 kHz internally whatever the source was, and WhatsApp, Telegram, Signal, Discord and WebRTC all use it.
Converting to MP3 is a lossy-to-lossy transcode, and Opus is the more efficient codec by a wide margin, so match the quality, not the number: a 32 kbps Opus voice note wants perhaps 96 to 128 kbps of MP3 to carry what it contains, and a 96 kbps Opus music file wants 192 kbps or more. MP3 was built for music in 1993 and is poor below about 96 kbps on anything, so a voice note converted at a matching bitrate will sound rougher than it did.
The sample rate stays at 48 kHz, which MP3 supports, so nothing is resampled; a mono voice note stays mono if you ask, which halves the file. Tags do not currently come across, which matters little for a voice note and more for a music collection.
When you want something else
Before converting, check whether the thing refusing the file is as fussy as it looks: every current browser, phone and computer plays Opus, and VLC plays everything. The genuine cases are car systems, older players, and software that lists its formats on the box.
ffmpeg does the same job and keeps the metadata: ffmpeg -i note.opus -c:a libmp3lame -q:a 4 -map_metadata 0 note.mp3. For a folder of voice notes it is one loop, and if the destination plays AAC, -c:a aac -b:a 96k gives a better file at a smaller size.
Frequently asked questions
What is an Opus file, and why do I keep getting them?
Opus is the codec built for voice over the internet in 2012 and now behind nearly every voice note, voice call and Discord recording, because it sounds good at tiny bitrates. Messaging apps export voice notes as .opus or .ogg, and that is where most people meet it.
Why will my phone or car not play it?
Every browser plays Opus, but the built-in music apps on iPhones, most car stereos, older MP3 players and a good deal of editing software do not. MP3 is the format all of them share, which is the whole reason for this page.
Which bitrate should I choose for a voice note?
128 kbps and mono. Speech carries far less information than music, and a 24 kbps Opus voice note is already more than fully carried by that. Higher only adds bytes.
Will it sound worse?
Very slightly, as a second lossy pass always does. For speech it is inaudible at 128 kbps; for music, encode at 192 kbps or above, because MP3 needs noticeably more bits than Opus to carry the same sound.
Is it the same as the OGG to MP3 page?
The same converter. OGG is the container, Opus is one of two codecs that live in it (Vorbis is the other), and both pages read both. This one exists because people search by the extension their phone showed them.
Is my voice note stored anywhere?
No. Voice notes are private conversations; the file is never stored and never sent anywhere.
Good to know: Every pass through a lossy encoder throws a little more away, and it never comes back. Converting between MP3, AAC, OGG and Opus is one such pass. If you are going to edit the sound, convert to WAV first, do the work, and encode once at the end. Opus can hold up to 255 channels; MP3 holds two, so anything beyond stereo is folded down.
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