How to Convert M4A to MP3: Quick & Easy Guide

What Is M4A and Why Convert to MP3?

M4A is an audio file format that uses the MPEG-4 container with AAC (Advanced Audio Coding) or Apple Lossless (ALAC) encoding. It is the default format for music purchased from the iTunes Store, audio exported from Apple applications, and recordings made with Voice Memos on iPhone.

While M4A offers better audio quality than MP3 at the same bitrate, there are practical reasons to convert:

• Device compatibility: Some older MP3 players, car stereos, and audio equipment do not support M4A
• Software compatibility: Certain audio editing tools, website builders, and CMS platforms only accept MP3
• Universal sharing: MP3 is the most widely recognized audio format — anyone can play it on any device
• Podcast distribution: Many podcast directories prefer or require MP3 submissions
• DJ software: Some DJ applications work best with MP3 files

The conversion from M4A to MP3 is lossy-to-lossy in most cases (AAC to MP3), which means some quality is lost. Choosing the right bitrate minimizes this loss to an imperceptible level.

M4A vs MP3: Key Differences

Understanding what you are converting helps you make better quality decisions:

Feature	M4A (AAC)	MP3
Codec	AAC (Advanced Audio Coding)	MPEG-1 Audio Layer III
Year introduced	1997	1993
Quality at 128 kbps	Good (comparable to MP3 at 160 kbps)	Acceptable
Quality at 256 kbps	Excellent (iTunes Store standard)	Very good
Max bitrate	320 kbps (standard), higher possible	320 kbps
DRM support	Yes (FairPlay in .m4p files)	No (inherently DRM-free)
Metadata	Excellent (iTunes-style tags)	Good (ID3 tags)
Device support	Modern devices, Apple ecosystem	Universal
Container	MPEG-4 (.m4a)	Native (.mp3)

Since AAC is a more efficient codec than MP3, an M4A file at 256 kbps contains roughly the same perceived quality as an MP3 at 320 kbps. When converting, you should use a higher MP3 bitrate than the M4A source to avoid noticeable quality loss. For a detailed codec comparison, see our AAC vs MP3 comparison.

Method 1: FFmpeg (Best Quality, Free)

FFmpeg with the LAME encoder produces the highest-quality MP3 output. LAME is the gold standard for MP3 encoding.

Basic Conversion (CBR 320 kbps)

ffmpeg -i input.m4a -c:a libmp3lame -b:a 320k output.mp3

This produces a constant bitrate MP3 at maximum quality. The LAME encoder handles the AAC-to-MP3 transcoding transparently.

VBR Conversion (Recommended for Music)

Variable bitrate encoding allocates more bits to complex passages and fewer to simple ones, producing better quality at a smaller average file size:

# VBR V0 (highest quality VBR, ~245 kbps average)
ffmpeg -i input.m4a -c:a libmp3lame -q:a 0 output.mp3

# VBR V2 (good quality, ~190 kbps average)
ffmpeg -i input.m4a -c:a libmp3lame -q:a 2 output.mp3

Preserving Metadata

FFmpeg preserves most metadata by default, but explicitly mapping it ensures nothing is lost:

ffmpeg -i input.m4a -c:a libmp3lame -q:a 0 \
  -map_metadata 0 -id3v2_version 3 output.mp3

The -id3v2_version 3 flag writes ID3v2.3 tags, which have the broadest player compatibility.

With Album Art

M4A files often contain embedded album artwork. To preserve it in the MP3:

ffmpeg -i input.m4a -c:a libmp3lame -q:a 0 \
  -map 0:a -map 0:v? -c:v copy \
  -map_metadata 0 -id3v2_version 3 output.mp3

The -map 0:v? maps the cover image if present (the ? prevents an error if there is no image), and -c:v copy copies it without re-encoding.

Bitrate Selection Guide

Source M4A Quality	Recommended MP3 Setting	Average Size (4 min)	Quality Preservation
ALAC (lossless)	320 kbps CBR or VBR V0	9-10 MB	Transparent to most listeners
AAC 256 kbps (iTunes)	VBR V0 or 320 kbps CBR	9-10 MB	Minimal loss
AAC 192 kbps	VBR V2 or 256 kbps CBR	6-8 MB	Good
AAC 128 kbps	192 kbps CBR or VBR V4	4-6 MB	Acceptable (source limited)
Voice memo / speech	128 kbps CBR	3.8 MB	Excellent for speech

For a deep dive into bitrate quality, see our audio bitrate quality guide. For understanding VBR versus CBR trade-offs, see our FLAC vs MP3 comparison which covers encoding modes in detail.

Method 2: Online Audio Converter

For quick conversions without installing software, use the audio converter or the MP3 converter.

Steps:

1. Navigate to the MP3 converter
2. Upload your M4A file
3. Select your preferred quality settings
4. Download the converted MP3

The online converter handles metadata preservation, bitrate selection, and format detection automatically. For converting multiple files, see our batch processing guide.

Method 3: iTunes / Apple Music (macOS/Windows)

If your M4A files are in your Apple Music or iTunes library, you can convert within the application itself.

Steps:

1. Open Music (macOS) or iTunes (Windows)
2. Go to Settings > Files > Import Settings (macOS) or Edit > Preferences > General > Import Settings (Windows)
3. Set "Import Using" to MP3 Encoder
4. Set "Setting" to Higher Quality (192 kbps) or Custom for 320 kbps
5. Click OK
6. Select the songs you want to convert
7. Go to File > Convert > Create MP3 Version

Apple Music creates new MP3 files alongside the originals. The originals are not modified.

Method 4: Batch Conversion (Multiple Files)

FFmpeg Batch Script

#!/bin/bash
mkdir -p mp3_output

for file in *.m4a; do
  [ -f "$file" ] || continue
  name="${file%.m4a}"
  echo "Converting: $file"
  ffmpeg -i "$file" -c:a libmp3lame -q:a 0 \
    -map_metadata 0 -id3v2_version 3 \
    "mp3_output/${name}.mp3" -y 2>/dev/null
  echo "Done: ${name}.mp3"
done

echo "All files converted."

PowerShell Batch Script (Windows)

New-Item -ItemType Directory -Force -Path "mp3_output"

Get-ChildItem -Filter "*.m4a" | ForEach-Object {
    $output = "mp3_output\" + $_.BaseName + ".mp3"
    Write-Host "Converting: $($_.Name)"
    ffmpeg -i $_.FullName -c:a libmp3lame -q:a 0 `
        -map_metadata 0 -id3v2_version 3 `
        $output -y 2>$null
}

Write-Host "All files converted."

For advanced batch workflows, see our how to batch convert files guide.

Handling DRM-Protected M4A Files

Some older M4A files purchased from iTunes before 2009 may be DRM-protected (with the .m4p extension). These files use Apple's FairPlay encryption and cannot be converted directly.

Legal options for DRM-protected files:

1. iTunes Match / Apple Music: Subscribe and re-download as DRM-free AAC (256 kbps)
2. Re-purchase: Buy the tracks again from iTunes (all current purchases are DRM-free)
3. CD method: Burn to audio CD in iTunes, then rip back as MP3 (quality loss from double conversion)

Note: Modern iTunes Store purchases (post-2009) and Apple Music downloads are all DRM-free M4A (iTunes Plus at 256 kbps AAC).

Common Issues and Solutions

Issue: "Unknown encoder libmp3lame"

This means FFmpeg was compiled without LAME support. Install a full FFmpeg build:

# macOS (Homebrew)
brew install ffmpeg

# Ubuntu/Debian
sudo apt install ffmpeg

# Windows: download from gyan.dev (full build)

Issue: Metadata Lost After Conversion

Add explicit metadata mapping:

ffmpeg -i input.m4a -c:a libmp3lame -q:a 0 \
  -map_metadata 0 -id3v2_version 3 \
  -metadata title="Song Title" \
  -metadata artist="Artist Name" \
  -metadata album="Album Name" \
  output.mp3

Issue: Album Art Missing in MP3

Some players do not display ID3v2.3 cover art. Try ID3v2.4:

ffmpeg -i input.m4a -c:a libmp3lame -q:a 0 \
  -map 0:a -map 0:v? -c:v copy \
  -id3v2_version 4 output.mp3

Issue: Gapless Playback Broken

Gapless playback (important for live albums and classical music) requires LAME's gapless encoding data. FFmpeg with LAME includes this by default, but verify with:

ffmpeg -i input.m4a -c:a libmp3lame -q:a 0 \
  -write_xing 1 output.mp3

Alternative Formats to Consider

Before converting to MP3, consider whether a different format might serve you better:

Format	Quality vs MP3	File Size vs MP3	Compatibility	Best For
Keep M4A (AAC)	Better	Smaller	Very good (modern devices)	If target devices support it
OGG Vorbis	Better	Similar	Good (Android, PC, web)	Open-source projects
FLAC	Lossless (best)	3-4x larger	Good (most modern devices)	Archival, audiophile use
WAV	Lossless (best)	5-10x larger	Universal	Audio editing intermediate
Opus	Much better	Smaller	Moderate (web, Android)	Streaming, VoIP

For more on choosing the right audio format, see our best audio format for music guide and best audio format for podcasts guide.

Frequently Asked Questions

Does converting M4A to MP3 lose quality?

Yes. Both AAC (M4A) and MP3 are lossy formats. Converting from one lossy format to another introduces an additional generation of compression. Using a high MP3 bitrate (320 kbps or VBR V0) minimizes the loss to an inaudible level for most people.

What bitrate should I use for M4A to MP3?

For music, use 320 kbps CBR or VBR V0. For podcasts and speech, 128-192 kbps is sufficient. Match or exceed the source M4A bitrate when possible.

Can I convert M4A to MP3 on iPhone?

Not natively. Use a web-based converter like the MP3 converter from Safari, or transfer the files to a computer and convert with FFmpeg or iTunes.

Will the conversion preserve my song tags and album art?

Yes, if you use FFmpeg with the -map_metadata 0 flag or the online converter, which preserves metadata by default. iTunes conversion also preserves tags.

Is M4A better than MP3?

Technically, yes. AAC (the codec inside M4A) is a newer, more efficient codec. At the same bitrate, AAC produces better audio quality than MP3. However, MP3's universal compatibility makes it the safer choice for sharing.

Conclusion

Converting M4A to MP3 is straightforward with the right tools and settings. Use FFmpeg with LAME at VBR V0 or 320 kbps for the best quality results. The MP3 converter and audio converter provide a quick browser-based alternative for users who prefer not to use the command line.

Always use the highest practical bitrate when converting between lossy formats, preserve metadata with the appropriate flags, and keep your original M4A files as masters in case you need to convert again in the future.

For more audio conversion guides, explore our how to convert WAV to MP3 guide, FLAC vs MP3 comparison, and audio bitrate quality guide.