Convert OPUS to AAC Online
Convert Opus voice messages to AAC for iPhone and Apple devices.
.opus · up to 100 MB
What it's for
Discord and Telegram voice ready for iPhone
Native Apple ecosystem
AAC has hardware acceleration in all Apple chips since 2003. Playback with no extra battery drain.
Podcasts and GarageBand
The resulting AAC is compatible with Apple Podcasts, GarageBand, Logic Pro, iMovie, and Final Cut Pro without additional conversion.
100% private
Your voice messages are never uploaded to any server. Local processing with FFmpeg.wasm.
Honest conversion
Lossy to lossy: we tell you exactly what happens. No quality miracles promised, but degradation is minimized.
How it works
Three steps, no hassle
Upload your Opus file
Drag or select your .opus file from Discord, Telegram, or WhatsApp. Up to 200 MB.
Conversion to AAC
FFmpeg.wasm transcodes Opus to AAC-LC in your browser. No servers, no waiting.
Download the AAC file
Get your .aac file ready to play on iPhone, iPad, iTunes, or any Apple device.
FAQ
Got questions?
iOS and macOS have native hardware support for AAC: every iPhone, iPad, and Mac includes an AAC decoder in the audio chip, ensuring playback without extra battery consumption. Opus, though technically superior and supported in Safari since iOS 15.4 (March 2022), lacks hardware acceleration on Apple chips, and third-party app support for Opus (Podcasts, Voice Memos) remains inconsistent. Converting Discord, Telegram, or WhatsApp voice messages (all in Opus) to AAC guarantees universal compatibility with the Apple ecosystem.
Yes, it is a lossy-to-lossy transcode: Opus is decoded to PCM and re-encoded to AAC-LC, adding a second generation of loss. For voice messages (32–64 kbps), the impact is minimal and generally imperceptible in normal listening. For music, use the highest available AAC bitrate (256 kbps). The conversion does not restore frequencies already discarded by the original Opus encoder.
Yes. Apple Podcasts, GarageBand, iMovie, Final Cut Pro, Logic Pro, and iTunes accept AAC natively. The resulting AAC is also compatible with AirPlay, HomePod, and Apple TV. For uploading to Apple Podcasts as an episode, AAC in an .m4a container is preferable — consider using the opus-to-m4a tool on this platform for that specific use case.
The conversion produces AAC-LC (Low Complexity), the most compatible AAC profile, used by iTunes, Apple Music, YouTube, and the vast majority of devices since 2003. HE-AAC and xHE-AAC are not used — they are more efficient at low bitrates but have lower compatibility with older players.
Vorbis Comment metadata from the Opus file (TITLE, ARTIST, ALBUM, DATE, TRACKNUMBER) are transferred to the resulting AAC in iTunes Atom format (MP4 metadata). Some Vorbis-specific fields without an equivalent in the iTunes metadata schema may not have an exact mapping.
For voice messages (Discord, Telegram, WhatsApp), 96–128 kbps AAC-LC is more than sufficient and produces files much smaller than the 256 kbps recommended for music. Voice intelligibility is excellent from 64 kbps AAC-LC. For podcasts intended for public distribution, Apple recommends 128 kbps mono or 192 kbps stereo as minimums in their technical requirements guide.
Convert Opus to AAC: Discord and Telegram voice messages for iPhone
Opus is the audio codec used by Discord, Telegram, WhatsApp Web, and all WebRTC-based applications for real-time voice communications. Its efficiency is exceptional: a Discord voice message occupies just 4 kB per second of audio at 32 kbps, and a high-quality Telegram call uses 64 kbps with latency below 5 ms. However, the Apple ecosystem has spent two decades building infrastructure based on AAC: iTunes, launched in January 2001, adopted AAC as its default store format in 2003; AirPods and HomePod use AAC over Bluetooth for maximum quality in the A2DP profile; Apple Music distributes its entire catalog in AAC-LC at 256 kbps. Apple Silicon chips (M1, M2, M3, M4) and iPhone A-series processors include dedicated AAC hardware decoding that guarantees playback with no battery impact. Opus support in the Apple ecosystem is more recent: Safari on iOS 15.4 (March 2022) added Opus playback support in the HTML audio element, and macOS Monterey 12.3 added it in the same cycle. However, this support does not extend uniformly to all system apps: the Podcasts app, Voice Memos, GarageBand, and iTunes for Windows do not accept Opus as input. For audio files that need to flow through the Apple ecosystem without friction, conversion to AAC is the practical solution.
Converting Opus to AAC is technically a lossy-to-lossy transcode that introduces a second generation of compression loss. This fact must be understood clearly: the resulting AAC file does not have better quality than the original Opus; it simply uses a different codec. The additional loss depends on the bitrate at both ends of the chain. For the most common use case, Discord voice messages encoded at 32 kbps Opus, the audio is already optimized for voice intelligibility with Opus's SILK profile, and re-encoding to AAC-LC at 96–128 kbps produces a result with practically identical intelligibility, since AAC-LC is also very efficient for voice at those bitrates. For musical audio recordings in Opus at 160 kbps or more, the impact of transcoding to AAC at 256 kbps is perceptible mainly in high-frequency extension (above 16 kHz), which may show differences in high-frequency instruments such as cymbals or triangles when listening through high-end headphones. Apple's recommended AAC bitrate for podcast distribution is 128 kbps for mono audio and 192 kbps for stereo, values that result in reasonably sized files with good quality. The produced AAC-LC is compatible with all Apple devices manufactured since 2003, Android since version 3.1 (2011), Windows Media Player since version 12 (Windows 7, 2009), and VLC, QuickTime, foobar2000, and virtually any audio player on the market.
Convertir.ai performs the Opus to AAC conversion entirely in the browser with FFmpeg.wasm. The process decodes the Opus with libopus to 48 kHz PCM (the native sample rate of Opus per RFC 6716 of September 2012), applies if necessary a resample to 44.1 kHz for compatibility with players that do not handle 48 kHz, and encodes with FFmpeg's AAC-LC implementation at the user-selected bitrate. The output container is AAC with a .aac extension, the most directly Apple-compatible format. Vorbis Comment metadata from the original Opus file are converted to MP4/iTunes atom format (©nam, ©ART, ©alb, ©day, trkn) for compatibility with iTunes and the iOS Music app. No audio is sent to external servers; all processing occurs locally on the user's device. There is no per-session file limit, no watermark, no subscription required, and the service is completely free. For the specific use case of creating podcasts for Apple Podcasts or using audio in GarageBand and Final Cut Pro, consider the opus-to-m4a tool which produces AAC in an M4A container, the preferred format for Apple tools for high-compatibility audio.