How to Convert WhatsApp Voice Messages (.opus) to MP3

What is an .opus file?

Opus is an open audio format, standardised in 2012, built to sound good at very small file sizes. That is exactly what a messaging app wants: a minute of speech in Opus takes a fraction of the space the same minute takes in MP3, with no loss you would notice on a phone.

WhatsApp uses it for every voice message, and so do many other apps — Telegram voice messages are Opus too, saved as .ogg instead of .opus. The file name does not change what is inside: an .ogg from Telegram and an .opus from WhatsApp hold the same kind of audio.

The catch is support. Opus is newer than the players many people still use, and a lot of software never added it. So the file that plays instantly inside WhatsApp can refuse to open the moment you move it to a computer.

Why would you want an MP3?

• To play it anywhere: MP3 opens on every computer, car stereo and media player
• To keep it: a voice message from someone you have lost, an important instruction, a record of something that was said
• To edit or transcribe it: older editors and some transcription services do not accept Opus
• To send it to someone without WhatsApp: an MP3 attaches to an email and plays on the other side

Step 1: Get the voice message out of WhatsApp

WhatsApp keeps voice messages inside the app, so the first step is saving one as a file. Menus move between versions, but the routes are roughly these:

• iPhone: press and hold the voice message, choose Forward, then tap the share icon and pick Save to Files
• Android: press and hold the voice message, tap the share icon at the top, and send it to Files, Drive or yourself by email. Android also keeps every voice message as a file in the WhatsApp folder on the phone, under Media → WhatsApp Voice Notes
• WhatsApp on a computer: open the message menu on the voice message and choose Download

Depending on the route, the file ends in .opus or .ogg. Either one works in the next step.

Step 2: Convert it to MP3

1. Open Opus to MP3 — or OGG to MP3 if your file ends in .ogg
2. Drop the file in, or click to choose it. You can add up to 20 at once
3. Leave the quality at the default 192 kbps, or choose 96 or 128 kbps — for a voice, either is plenty and keeps the file smaller
4. Download the MP3. With several files, save them one by one or all together as a ZIP

The first audio conversion downloads the conversion engine into your browser, which takes a moment once; after that it is cached and conversions start straight away.

Why it matters that the file is not uploaded

Voice messages are about as personal as files get — family, health, work, things said in confidence. Most online converters work by uploading your file to their server, converting it there and keeping a copy for a while. Here the conversion runs on your own device, in the browser tab, so there is no copy anywhere else.

You can check rather than take that on trust: after one conversion, turn off your Wi-Fi without reloading the page and convert another file. It still works, because nothing needs a server.

MP3 or WAV?

What converting will not do

• It will not improve the sound. A voice message is recorded small to begin with; converting it changes the format, not the recording. Background noise and a muffled microphone stay exactly as they were
• The MP3 will be bigger than the .opus. MP3 needs several times the data to match what Opus does at small sizes, so a larger file is expected, not a sign that something went wrong
• It cannot open a voice message that never left WhatsApp. Converters work on files; the message has to be saved as one first (step 1)

If you only want to listen on a computer

You do not always need to convert. Chrome, Edge and Firefox can play an .opus or .ogg file dropped into a new tab, and the free VLC player opens both. Converting is for when you need the file to work somewhere else — another program, another device, another person.