Bulk Convert AAC to OPUS Online — Modern, Royalty-Free Codec
OPUS offers better compression than AAC, ideal for streaming and WebRTC.
Drop up to 50 files at once — no install, no sign-up required.
Drop AAC/M4A Files Here
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How it works
- 1 · Drop your files
Drag & drop or choose AAC/M4A files. No account required on Free—paid plans unlock bigger batches, higher limits, and priority queues.
- 2 · We convert securely
Processed on our dedicated servers. Encrypted in transit & at rest. We never store filenames—only file types & sizes for accounting.
- 3 · Download & auto-delete
Grab your OPUS files in seconds. Files delete automatically after 1 hour. Delete anytime after downloading with one click.
AAC (Advanced Audio Coding) is the successor to MP3, standardized by MPEG in 1997 and subsequently adopted as the default format for YouTube, Apple Music, and most streaming platforms. Achieving compression ratios of 8:1 to 12:1, AAC delivers better quality than MP3 at the same bitrate—128 kbps AAC typically matches 160-192 kbps MP3. It's the underlying codec in M4A files (AAC audio in an MP4 container) and the audio component of most video files.
Learn more: AAC on Wikipedia
Raw AAC files (with .aac extension) are less common than containerized versions (.m4a, .mp4), but they're used in broadcast, streaming pipelines, and as extracted audio from video. AAC supports sample rates up to 96 kHz and up to 48 audio channels, including 5.1 and 7.1 surround configurations—making it suitable for professional multichannel content. For maximum compatibility with minimal quality loss, AAC at 256 kbps is often the sweet spot between MP3's universality and FLAC's fidelity.
OPUS is a modern, open-source, royalty-free audio codec developed by Xiph.Org Foundation and IETF, standardized in RFC 6716 in September 2012. It was designed to replace both Vorbis (for music) and Speex (for voice), combining the best of both into a single codec. OPUS achieves exceptional quality at low bitrates—transparent quality at 128 kbps for music, and near-transparent voice at just 32 kbps. It supports bitrates from 6 kbps to 510 kbps and sample rates from 8 kHz to 48 kHz.
Learn more: Opus on Wikipedia
OPUS is the mandatory audio codec for WebRTC, making it the native format for video calls (Discord, Zoom, Google Meet, Teams) and voice messaging (WhatsApp, Telegram). It excels at both speech and music, adapting dynamically to content. OPUS files use the Ogg container (.opus extension) and play in all modern browsers (Chrome, Firefox, Edge, Safari 15+), VLC, and most media players from 2015 onward. For streaming, voice chat, podcasts, and any application where quality-per-bit matters, OPUS is the current state of the art.
Frequently Asked Questions
Why convert AAC to OPUS?
Will converting AAC to OPUS improve quality?
What's the difference between .aac and .m4a files?
What bitrate does this converter use for OPUS?
Will my iPhone voice memos convert properly?
Do you preserve metadata from AAC files?
Is OPUS supported on Apple devices?
What are the limits for this converter?
| Tier | Max File Size | Max Files/Batch | Parallel Processing |
|---|---|---|---|
| Guest/Free | 50 MB | 50 files | 3 at once |
| Pro | 2048 MB | 1000 files | 6 at once |
Note: File size limits are specific to this converter. Batch and parallel processing limits apply to all images converters site-wide. See all converter limits →
How are credits calculated for this conversion?
Cost: 1 credit per 5 minutes
How it works:
- Files up to 5 minutes: 1 credit
- 6-10 minutes: 2 credits
- 11-15 minutes: 3 credits
- 16-20 minutes: 4 credits
Example: A 10-minute file = 2 credits. A 180-minute (3h) audiobook = 36 credits.
Why per-minute? Audio conversion time scales with content duration, not file size. Longer audio requires proportionally more processing.
What are my daily and monthly credit limits?
Credit allocations vary by account tier:
| Tier | Daily Limit | Monthly Limit |
|---|---|---|
| Guest | 100 credits/day | — |
| Free | 100 credits/day | — |
| Pro | — | 12,000 credits/month |
Daily credits (Guest & Free tiers) reset every day at midnight UTC. Monthly credits (Pro) reset on your billing cycle date.
Note: With 1 credit per 5 minutes, audio files under 5 MB cost 1 credit each. Pro users can convert 12,000 audio files per month.
Answers at a Glance
Quick answers to common questions.
- Are my files secure?
- How long do you keep my files?
- What metadata do you keep?
- What happens after I drop a file?
- Why are conversions so fast?
- How do you measure performance?
- What are the exact limits for each plan?
- Can I process files in bulk?
- Why did my file fail to convert?
- Do you use my files to train AI?
What's New in AAC to OPUS
Latest improvements to this converter
Initial release of AAC to OPUS converter with high-quality OPUS encoding.
Need to get more done? Pro starts from $5.
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