What is an .opus file, and how do you open or transcribe it?
Short answer
An .opus file is audio in the Opus format, which WhatsApp uses for voice notes (sometimes saved as .ogg). Chrome, Firefox, Edge and VLC can play it. You don't need to convert it to mp3 to transcribe it; Dolcenota accepts .opus and .ogg files directly.
If you've saved a WhatsApp voice note to your computer, you've probably met a file ending in .opus (or sometimes .ogg) that won't open with a double-click. It's not broken: Opus is a modern audio format that many players still don't support out of the box.
Here's what an .opus file is, how to play it, whether you need to convert it, and how to turn it into text.
What Opus is
Opus is an open, royalty-free audio codec designed for speech and music over the internet. It sounds good at very small file sizes, which is why WhatsApp, many voice-chat apps and web calls use it. An .opus file is usually Opus audio inside an Ogg container, so you'll also see .ogg.
How to play an .opus file
- Chrome, Firefox and Edge play .opus files: drag the file into a browser tab.
- VLC (free, Windows, Mac, Linux) plays it.
- On a phone, WhatsApp plays its own voice notes; a saved .opus file may need VLC or a browser.
- Some built-in players don't support it, which is why it looks broken.
Do you need to convert it to mp3?
Only if the program you want to use doesn't accept Opus. Converting re-encodes the audio, which loses a little quality and adds a step. For transcription, you don't need to convert: Dolcenota accepts .opus and .ogg files directly.
How to transcribe an .opus file
- Open Dolcenota in your browser and tap "Upload file".
- Choose the .opus file (or several voice notes at once to get one transcript).
- In a few minutes you get the text, a summary and the option to ask questions about it; export to Word, PDF or TXT.
Frequently asked questions
Is an .opus file safe?
Yes. It's an ordinary audio file. As with any file, open it only if it comes from someone you trust.
What's the difference between .opus and .ogg?
Ogg is a container and Opus is the audio codec inside it. WhatsApp voice notes are Opus audio, saved with either extension.
Can I transcribe WhatsApp voice notes without converting them?
Yes. Upload the .opus files as they are; there's no need to convert them to mp3.
Why won't my computer play it?
Some built-in media players don't include Opus support. Open it in a web browser or in VLC instead.
Is transcribing it free?
Dolcenota's free plan includes 60 minutes a month, with summaries and export.
Turn your .opus files into text
Upload WhatsApp voice notes as they are and get the transcript, a summary and answers. Free to start.
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