Convert.FAST

Convert AAC to MP3 Online — Apple Audio to Universal Playback

Convert iTunes AAC and M4A files to universal MP3 that plays anywhere.

Drop up to 50 files at once — no install, no sign-up required.

Drop AAC/M4A Files Here

50 MB or 2 hours per file Up to 50 files 3 parallel conversions 1 credit per 5 minutes

Encrypted EU Servers Auto-delete 1h

Median AAC → MP3 time (last 10k jobs): 705ms per minute

How it works

  1. 1 · Drop your files

    Drag & drop or choose AAC/M4A files. No account required—paid plans unlock bigger batches, higher limits, and priority queues.

  2. 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. 3 · Download & auto-delete

    Grab your MP3 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.

MP3 (MPEG-1 Audio Layer III) revolutionized digital audio when it was standardized in 1993 by the Fraunhofer Society. Using psychoacoustic compression, MP3 removes audio frequencies that humans typically cannot perceive, achieving 10:1 compression or better while maintaining excellent subjective quality. MP3 supports sample rates from 8-48 kHz and 16-bit audio. At 256 kbps, most listeners cannot distinguish MP3 from the original source in blind tests.

Learn more: MP3 on Wikipedia

MP3 remains the most universally compatible audio format, supported by every music player, smartphone, computer, and web browser. While newer codecs like AAC and Opus offer marginally better compression efficiency, MP3's ubiquitous support makes it the safest choice for sharing audio. The format's patents expired in 2017, making it completely free to use without licensing concerns.

Frequently Asked Questions

What is the difference between AAC and MP3?

AAC (Advanced Audio Coding) is a newer, more efficient codec than MP3. It provides better quality at the same bitrate. AAC is the default audio format for Apple devices (iTunes, iPhone, iPad). MP3 is older but universally supported on virtually every device.

Will converting AAC to MP3 reduce audio quality?

Yes. Converting between lossy formats (lossy-to-lossy) means some additional quality loss. However, we encode at 320 kbps MP3 (maximum quality) to preserve excellent quality. The difference is typically negligible for most listeners. If you have a lossless source, convert from that instead.

Why would I convert AAC to MP3?

Compatibility. While AAC is popular on Apple devices, MP3 has near-universal support. Some older devices, car stereos, and software may not recognize AAC/M4A files. Converting to MP3 ensures your audio plays everywhere.

What about M4A files?

AAC audio can come in two forms: raw ADTS streams (often .aac files from streaming or recording) or wrapped in an M4A container (.m4a files from iTunes/Apple Music). Our converter handles both. For iTunes-specific files, you can also use our M4A to MP3 converter.

What MP3 settings do you use?

We encode at 320 kbps MP3 (maximum quality) using the high-quality LAME encoder. This is the highest standard MP3 bitrate, ensuring excellent quality for the format.

What happens to iTunes metadata?

Yes, it transfers. Text metadata (title, artist, album, genre) and cover art transfer automatically. AAC tags are automatically mapped to ID3 tags during conversion.

How long can my audio files be?

Duration limits depend on your plan: Guest/Free: 120 minutes, Pro: 600 minutes (10 hours), Business: 3000 minutes (50 hours). This accommodates everything from songs to full audiobooks and podcasts.

What are the limits for this converter?

TierMax File SizeMax Files/BatchParallel Processing
Free50 MB50 files3 at once
Pro500 MB200 files6 at once
Business2048 MB1000 files10 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:

TierDaily LimitMonthly Limit
Free50 credits/day
Pro10,000 credits/month
Business30,000 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.

Choose Your Plan

Limits shown for AAC to MP3 conversion. One subscription unlocks the entire Tools.FAST Network. Plans cover Convert.FAST, Compress.FAST, PDF.FAST (soon), and all future tools.

Monthly Annual 4 Months Free

Free

$0

For occasional personal use

  • 50 MB per file
  • 50 files per batch
  • 3 parallel conversions
  • 50 credits/day
  • Standard priority
  • Email support
Sign Up Free

No sign-up required. Create an account for your own credit pool.

Popular

Pro

$9 /month

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

$19 /month

1 seat

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 AAC to MP3

Latest improvements to this converter

Last updated December 16, 2025
Dec 16, 2025

Initial release of AAC to MP3 converter with LAME encoding.