Convert OPUS to M4A Online — Apple Compatible
Get M4A files that work perfectly with iTunes, iPhone, iPad, and Apple ecosystem.
Drop up to 50 files at once — no install, no sign-up required.
Drop OPUS Files Here
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How it works
- 1 · Drop your files
Drag & drop or choose OPUS files. No account required on Free—paid plans unlock bigger batches.
- 2 · We convert securely
Processed on our dedicated servers. Encrypted in transit & at rest.
- 3 · Download & auto-delete
Grab your M4A files in seconds. Files delete automatically after 1 hour.
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.
M4A (MPEG-4 Audio) is Apple's container format for AAC-encoded audio, introduced with iTunes in 2001. AAC itself was standardized by MPEG in 1997 (MPEG-2) and enhanced in 1999 (MPEG-4), achieving compression ratios of 8:1 to 12:1. M4A has become synonymous with Apple's ecosystem—it's the default for iTunes purchases, Apple Music downloads, and iPhone voice memos. At equivalent bitrates, AAC delivers better quality than MP3, with 256 kbps M4A typically matching 320 kbps MP3.
Learn more: M4A on Wikipedia
M4A supports sample rates up to 96 kHz and up to 48 audio channels, including surround sound configurations. The main limitation is compatibility—while modern devices handle M4A well, older hardware and some software (particularly on Windows and Linux) may not support it natively. For universal playback, MP3 remains the safer choice. M4A excels for Apple-centric workflows: syncing to iPhone, organizing in iTunes/Music app, or archiving Apple Music downloads.
Frequently Asked Questions
Why convert OPUS to M4A?
What's the difference between M4A and AAC?
What bitrate do you use?
What are the limits for this converter?
| Tier | Max File Size | Max Files/Batch | Parallel Processing |
|---|---|---|---|
| Free | 50 MB | 50 files | 3 at once |
| Pro | 500 MB | 200 files | 6 at once |
| Business | 2048 MB | 1000 files | 10 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 (minimum)
- 6-10 minutes: 2 credits
- 11-15 minutes: 3 credits
- 16-20 minutes: 4 credits
Example: A 10-minute file = 1 credit. 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 |
|---|---|---|
| Free | 50 credits/day | — |
| Pro | — | 10,000 credits/month |
| Business | — | 30,000 credits/month |
Daily credits (Free tier, including guests) reset every day at midnight UTC. Monthly credits (Pro & Business) 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 10,000 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?
Choose Your Plan
Limits shown for OPUS to M4A conversion. One subscription unlocks the entire Tools.FAST Network. Plans cover Convert.FAST, Compress.FAST, PDF.FAST (soon), and all future tools.
Free
For occasional personal use
- 50 MB per file
- 50 files per batch
- 3 parallel conversions
- 50 credits/day
- Standard priority
- Email support
No sign-up required. Create an account for your own credit pool.
Pro
For independent work
- 500 MB per file
- 200 files per batch
- 6 parallel conversions
- 10,000 credits/month across Tools.FAST
- High priority
- Email & chat support
- One subscription for the entire Tools.FAST network
Business
For production scale
- 2 GB per file
- 1000 files per batch
- 10 parallel conversions
- 30,000 credits/month across Tools.FAST
- Add seats to invite team members
- Highest priority
- Priority email & chat support
- One subscription for the entire Tools.FAST network
How Credits Work
- Usually 1 credit per conversion. Exact cost shown before you start.
- Credits refresh monthly on your billing cycle.
- Unused credits roll over, capped at your plan's monthly amount.
- One subscription, all sites. Works across Convert.FAST, Compress.FAST, and future tools.
What's New in OPUS to M4A
Latest improvements to this converter
Initial release of OPUS to M4A converter with AAC encoding.