Convert OPUS to MP3 Online
Convert Discord voice messages, WhatsApp audio, and Telegram voice notes to MP3. Free, in your browser.
.opus · up to 100 MB
What it's for
OPUS to MP3: universal voice messages
Discord, WhatsApp, Telegram
Convert voice messages from the three major messaging apps to MP3 playable on any device.
100% private
Your voice recordings are never uploaded to any server. FFmpeg.wasm processes everything in your browser.
Optimal voice quality
MP3 at 128 kbps for voice: transparent quality, manageable size, compatible with everything.
No installation
No need to install VLC or any codec pack. Works directly in Chrome, Edge, or Firefox.
How it works
Three steps, no hassle
Upload your OPUS file
Drag or select your .opus file — typically voice messages from Discord, WhatsApp, or WebRTC recordings. Up to 50 MB, no signup.
Automatic conversion
FFmpeg.wasm decodes the Opus stream and re-encodes to MP3 (libmp3lame) directly in your browser. The file never leaves your device.
Download your MP3
Download the MP3 ready to play on any device, import into a DAW, or share anywhere.
FAQ
Got questions?
Opus is an audio codec defined in IETF RFC 6716, published in September 2012. It was developed by Jean-Marc Valin (Xiph.org, author of CELT) and Koen Vos (Skype, author of SILK), merging both projects into a single open standard. Opus delivers quality superior to MP3 and AAC at half the bitrate. Discord, WhatsApp, Telegram, Google Meet, and Firefox all use Opus internally for all voice communications. The problem is that most desktop audio players — Windows Media Player, iTunes, car stereos, smart TVs — do not include native support for the OGG+Opus container, so the .opus file simply won't open. Converting to MP3 makes it playable on 100% of existing devices.
Discord stores voice messages sent from the desktop or mobile client as .opus files on its servers. To download them: open the voice message in Discord, click the three-dot menu next to the message, and select 'Open Link' or 'Download'. Discord bots like DiscordAudioRecorder also export recordings in .opus format. Once you have the .opus file, upload it here to convert to MP3.
No content is lost. WhatsApp stores voice messages in Opus format (.opus extension, or .enc on some Android devices once decrypted). Converting to MP3 involves minimal re-encoding loss at 128 kbps — more than sufficient for voice. The duration, spoken content, and perceptible quality are identical to the original. After conversion you can play the message in any audio app or import it into editing projects.
For voice, Opus at 32 kbps perceptibly outperforms MP3 at 128 kbps — which is exactly why Discord, WhatsApp, and Telegram use Opus: smaller files with better voice clarity. When converting Opus to MP3 there is an unavoidable slight degradation from re-encoding, but at 128 kbps the difference is imperceptible to the human ear for voice content. For music, the Opus→MP3 roundtrip loss is more noticeable; if you have the uncompressed original, it is always preferable to encode directly from WAV or FLAC.
Yes. Telegram saves voice messages and voice notes in OGG Opus format (.ogg with Opus codec inside). To download them from the Telegram app: long-press the message → 'Forward to Saved Messages' → download in Telegram Desktop. You get an .ogg file containing Opus audio. This tool converts them correctly to MP3 regardless of whether the extension is .opus or .ogg with Opus inside.
No signup, no quantity limit, no watermark. Conversion happens entirely in your browser with FFmpeg.wasm. You can convert as many .opus files as you need in a session. The practical limit is file size (50 MB per file), more than enough for any typical voice message or WebRTC recording.
Convert OPUS to MP3: Discord voice messages, WhatsApp audio, Telegram voice notes
Opus is the most advanced open-source audio codec available today. It was standardized by the IETF in RFC 6716, published in September 2012, as the result of merging two prior projects: CELT, developed by Jean-Marc Valin at Xiph.org (the same team behind Ogg Vorbis, FLAC, and Theora), and SILK, the proprietary voice codec developed internally by Skype and donated by Microsoft to the standardization process. This merger produced a unique codec capable of handling both low-latency conversational voice at 6-40 kbps and high-quality music audio up to 510 kbps, with transparent switching between modes. The result is that Opus at 64 kbps delivers quality equivalent to or better than MP3 at 128 kbps, and Opus at 32 kbps surpasses MP3 at 96 kbps for voice content. Today Discord uses Opus for all voice channels and voice messages, WhatsApp uses Opus for all voice notes, Telegram uses Opus for voice messages and voice notes, Google Meet, Zoom, and Microsoft Teams use Opus as the primary audio codec in WebRTC calls, and Firefox, Chrome, and Edge use Opus as the native codec in the browser MediaRecorder API. The scale of Opus adoption in messaging applications means that the volume of .opus files requiring conversion to MP3 grows daily. The combination of Opus being technically superior yet practically incompatible with legacy players creates a persistent conversion need that is unlikely to disappear as long as the installed base of older devices remains large. The process is completely free and requires no signup or installation of additional software.
The practical problem with .opus files is not technical but one of legacy compatibility. The vast majority of popular desktop audio players, including Windows Media Player which does not include the Opus decoder by default in Windows 10 and 11, iTunes and Apple Music on macOS, smart TVs from Samsung and LG predating 2020, car audio units up to 2019, and many portable audio players, cannot open a .opus file without installing additional codecs. Furthermore, audio editing platforms such as Adobe Premiere Pro, Final Cut Pro X, and older versions of Audacity do not natively import .opus files. This compatibility gap is structural and shows no signs of closing in the short term: devices with old firmware do not receive codec updates, and the installed base of players without Opus support is enormous. Car audio systems and smart TVs update their firmware with much less frequency than smartphones, meaning Opus incompatibility in these devices will persist well into the 2030s. This ensures that demand for OPUS to MP3 conversion will remain high for many years to come. The widespread use of Opus in WebRTC applications also means developers frequently need MP3 exports for compatibility with legacy media players, content management systems, and broadcast workflows that require MP3 as a standard delivery format. All conversion occurs locally in the user's browser via FFmpeg.wasm, ensuring complete privacy. There is no limit on the number of files per session and no usage restrictions on any available function. The tool is compatible with Chrome, Edge, Firefox, and Safari on desktop and mobile without any additional configuration.
Convertir.ai performs the OPUS to MP3 conversion entirely in the browser using FFmpeg.wasm, the WebAssembly port of the FFmpeg engine compiled with support for the libopus decoder and the libmp3lame encoder. The process reads the OGG container (the most common for Opus, with .opus extension) or WebM (used by Chrome's MediaRecorder), extracts the Opus stream, decodes it with libopus to 48 kHz floating-point PCM (Opus's native sample rate per the RFC 6716 specification), applies if necessary a resample to 44.1 kHz (the standard MP3 frequency), and re-encodes with libmp3lame at 128 kbps stereo or mono depending on the source stream. The bitrate of 128 kbps for MP3 is the standard transparency threshold for voice content: there is no perceptible difference from the original Opus for that type of content. For WhatsApp voice messages typically recorded in mono 16 kHz and Discord at 32 kHz stereo or mono, the result is an MP3 with perceptually identical quality to the original. The choice of 128 kbps as the default bitrate reflects the industry consensus and guarantees compatibility with 100 percent of existing audio playback software and hardware. All processing occurs in memory within the browser context, with no data transfer to external servers, ensuring complete privacy for personal or confidential voice recordings. No signup, no quantity limit, no watermark. The resulting file follows IETF and Xiph.org open standards for maximum compatibility with audio players and software. The process is completely free and requires no signup or installation of additional software. All conversion occurs locally in the user's browser via FFmpeg.wasm, ensuring complete privacy.