OPUS to AAC Converter
Convert OPUS to AAC online for free. Fast, secure, and high-quality conversion with no sign-up or software required.
Maximum file size is 1GB
How it works
Three steps to your converted file
Everything happens in your browser tab - upload, pick a format, download. The heavy lifting runs on our servers.
Upload your file
Drag and drop, click to browse, or paste a URL. Batches take up to 20 files at once - 230+ input formats across video, audio, image, document, and archive types.
Choose an output format
Pick from over a hundred output formats. Filter by category or search by name - every option is open to everyone, no account needed.
Convert & download
Hit Convert and grab your download link moments later. Originals are erased when the job completes; results are cleared within about an hour.
What is an OPUS file?
Opus is a modern, royalty-free lossy audio codec standardized by the IETF (RFC 6716). It combines the SILK codec (originally built for Skype) with the CELT codec to deliver high audio quality at very low bitrates and latency, scaling smoothly from low-bitrate speech to high-fidelity music. Its efficiency and low latency have made it the default codec for WebRTC, Discord, WhatsApp, and Microsoft Teams voice and video calls.
How to open an OPUS file
Opus files play natively in VLC Media Player, Firefox, and Chrome, and most modern operating systems include native decoder support. On older systems or media players without Opus support, the format can be converted to a more universally compatible format like MP3 or WAV.
OPUS Technical Info
- Full Name
- Opus Interactive Audio Codec
- Developed By
- Xiph.Org Foundation / IETF
- Initial Release
- 2012
- MIME Type
- audio/opus
What is an AAC file?
Advanced Audio Coding (AAC) is a lossy digital audio compression standard defined by ISO/IEC 13818-7 (MPEG-2) and ISO/IEC 14496-3 (MPEG-4). Developed by a consortium including Bell Labs, Fraunhofer IIS, and Dolby Laboratories as the successor to MP3, AAC utilizes the Modified Discrete Cosine Transform (MDCT) algorithm and perceptual noise shaping to discard imperceptible signal components. It supports up to 48 audio channels, arbitrary sample rates, and utilizes extensions such as Spectral Band Replication (SBR) to achieve higher fidelity at lower bitrates than predecessor formats.
How to open an AAC file
AAC serves as the default audio container for Apple's iTunes and iOS devices, ensuring native support within the macOS Core Audio framework and Apple Music. Windows 10 and 11 provide native decoding support via the Groove Music and Windows Media Player applications. For cross-platform playback or advanced stream analysis, users should utilize VLC Media Player or FFmpeg, which contain the necessary libavcodec libraries to decode AAC streams without external codec packs.
AAC Technical Info
- Full Name
- Advanced Audio Coding
- Developed By
- Bell Labs, Fraunhofer IIS, Dolby, Sony, Nokia
- Initial Release
- 1997
- MIME Type
- audio/aac
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Why RunConvert
The fastest way to convert any file
Purpose-built for speed, privacy, and breadth of format support.
Convert OPUS to AAC in seconds
Every OPUS to AAC conversion runs on our servers, so your device stays fast and the output quality stays intact.
Fast, cloud-powered
No queue, no waiting. Files are processed on high-performance servers and returned in seconds, even for large files.
Secure & private
Encrypted in transit and never shared with anyone. Uploads are erased the moment your job completes, and results shortly after.
Free - no account needed
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Developer API
Convert OPUS to AAC via API
Automate OPUS to AAC conversions in three steps: create a job, upload your file, then poll for the result.
# 1. Create job
curl -X POST https://api.runconvert.com/v3/jobs \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"tag": "opus-to-aac",
"tasks": {
"upload-file": {
"operation": "import/upload"
},
"convert": {
"operation": "convert",
"input": "upload-file",
"output_format": "aac"
},
"export-result": {
"operation": "export/url",
"input": "convert"
}
}
}'
# 2. Upload your file (use upload_url from the response)
curl -X PUT "$UPLOAD_URL" --upload-file input.opus
# 3. Poll for result
curl https://api.runconvert.com/v3/jobs/$JOB_ID?include=tasks \
-H "Authorization: Bearer YOUR_API_KEY"Replace YOUR_API_KEY with your RunConvert API key. Get your free API key at runconvert.com/api.