A native macOS application for creating MP3 CDs from your music library. Drag folders of music, and the app automatically converts everything to MP3 format optimized to fit on a 700MB CD.
MP3 CD Burner takes the hassle out of creating MP3 CDs:
- Smart bitrate calculation - Automatically determines the optimal bitrate to maximize audio quality while fitting on a standard 700MB CD
- Background encoding - Files start converting immediately as you add folders, no waiting
- Lossless-aware - FLAC and WAV files are converted to MP3; existing MP3s are copied directly when possible
- One-click burning - When encoding completes, just click "Convert & Burn" to create your CD
| Format | Type | Handling |
|---|---|---|
| MP3 | Lossy | Copied directly |
| FLAC | Lossless | Converted to MP3 at calculated bitrate |
| WAV | Lossless | Converted to MP3 at calculated bitrate |
| AIFF | Lossless | Converted to MP3 at calculated bitrate |
| AAC/M4A | Lossy | Transcoded to MP3 at source bitrate |
| OGG | Lossy | Transcoded to MP3 at source bitrate |
| Opus | Lossy | Transcoded to MP3 at source bitrate |
| ALAC | Lossless | Converted to MP3 at calculated bitrate |
Drag album folders from Finder into the app window. The app will:
- Scan each folder for audio files
- Extract album metadata (artist, album name, year) from tags
- Begin converting files in the background immediately
You can also drag a parent folder containing multiple albums - the app will detect and add each album separately.
Create custom playlists by dragging individual audio files (not folders) into the app. This creates a "Mixtape" that you can name and customize:
- Drag audio files from different albums into the app
- A new mixtape is created automatically
- Click the edit icon to open the Track Editor to rename, reorder, or add more tracks
Click the edit icon on any folder to open the Track Editor window:
For Albums:
- View all tracks with metadata (title, artist, duration)
- Drag tracks to reorder them
- Click the checkbox to exclude/include individual tracks
- Excluded tracks are dimmed and won't be burned to CD
For Mixtapes:
- All album features plus:
- Drag additional audio files from Finder to add them
- Click the × button to remove tracks
- Edit the mixtape name in the title bar
As folders are added:
- Each folder shows a progress bar during encoding
- The status bar shows total files, duration, and source size
- The calculated bitrate updates based on total content
- ISO size appears once all folders are encoded
The status bar shows:
- Source: Total size of your original files
- Target: 700 MB (standard CD capacity)
- Bitrate: Calculated optimal bitrate (or your manual override)
- ISO: Final ISO size after encoding
If the ISO exceeds 700 MB, you'll need to remove some folders, or perhaps customize the bitrate on lossless files.
Click on the bitrate display to manually override it. This lets you:
- Increase bitrate if you have room to spare
- Decrease bitrate to fit more music
- The asterisk (e.g., "285 kbps*") indicates a manual override
When you change the bitrate, lossless files are automatically re-encoded.
If the calculated bitrate produces an ISO with extra space, you can increase the bitrate and re-encode to maximize quality. Adjust until the ISO size is as close to 700 MB as desired without exceeding it.
Once all folders show green checkmarks:
- Click Convert & Burn
- Enter a volume label for your CD
- Insert a blank CD-R or CD-RW when prompted
- Wait for burning to complete
After burning, click Burn Another to make additional copies without re-encoding.
Save your folder list and settings for later use.
File > Save (Cmd+S) offers two options:
| Option | File Size | Use Case |
|---|---|---|
| Metadata Only | ~1 KB | Quick save; files will re-encode when reopened |
| Include Audio Files | ~600+ MB | Portable bundle; no re-encoding needed |
- Saves folder paths, volume label, and bitrate settings
- Very small file size
- When reopened, validates that source folders still exist
- Re-encodes any folders that have changed
- Creates a folder bundle containing the profile and all converted MP3s
- Large file size (similar to final ISO)
- Completely portable - can be moved to another Mac
- Opens instantly with no re-encoding needed
- Ideal for archiving a "ready to burn" state
- Folder paths and order
- Volume label (if set)
- Manual bitrate override (if set)
- Conversion state (which folders are already encoded)
- ISO state (if an ISO has been generated)
- New (Cmd+N) - Clear all folders and start fresh
- New Mixtape (Cmd+Shift+N) - Create an empty mixtape to add tracks to
- Open (Cmd+O) - Open a saved burn profile
- Save (Cmd+S) - Save current state as a burn profile
- Set Volume Label - Change the CD volume label
- Display Settings - Toggle which metadata appears on folder cards:
- File count
- Original size
- Converted size
- Source format
- Source bitrate
- Final bitrate
- Simulate Burn - Test the burn process without using a disc
- Embed Album Art - Include cover art in output MP3 files
- Open Output Folder - Reveal the temporary encoding directory
- Open Log Folder - Reveal the log directory for troubleshooting
Built with GPUI, Zed's native Rust UI framework. The app uses:
- Global file queue - All tracks across all folders are queued together for maximum throughput
- Parallel encoding - 2-8 worker threads (based on available CPU cores) pull from the shared queue
- FFmpeg for all audio conversion (bundled with the app)
- hdiutil for ISO creation and CD burning (macOS built-in)
The app uses a two-phase approach with intelligent file handling:
Phase 1 - Lossy files:
- All lossy files from all folders are queued together
- MP3s are copied directly (preserving original quality)
- Other lossy formats (AAC, OGG, Opus) are transcoded at their source bitrate
Phase 2 - Lossless files:
- After Phase 1 completes, the app measures total lossy output size
- Calculates optimal bitrate for lossless files to maximize quality while fitting on CD
- All lossless files (FLAC, WAV, AIFF, ALAC) are queued and encoded at the calculated bitrate
This ensures maximum audio quality: lossy files keep their original quality, while lossless files get the highest bitrate that will fit.
Future: Re-encode high-bitrate MP3s when necessary to fit on CD.
MP3 files are copied directly to preserve original quality. When the "Embed Album Art" option is enabled, MP3s without embedded artwork are re-encoded to include the album's cover art.
Uses macOS native tools:
hdiutil makehybrid- Creates ISO-9660 + Joliet hybrid imagehdiutil burn- Burns with progress tracking via puppetstrings
CD-RW discs are detected and can be erased before burning.
- Temporary files:
/tmp/mp3cd_output/session_*/ - Profiles: Saved wherever you choose (Documents recommended)
- Settings:
~/Library/Application Support/mp3cd-gpui/ - Logs:
~/Library/Logs/MP3-CD-Burner/mp3cd-burner.log
The log file captures debug-level information and can be helpful for troubleshooting. Logs rotate automatically when they exceed 10MB.
- macOS 12.0 (Monterey) or later
- Optical drive (internal or external USB)
- Blank CD-R or CD-RW discs
# Clone the repository
git clone https://github.com/jerimiah797/mp3cd-burner.git
cd mp3cd-burner
# Install ffmpeg (required for audio conversion)
# Option 1: Use Homebrew (easiest)
brew install ffmpeg
mkdir -p resources/bin
cp $(which ffmpeg) resources/bin/
# Option 2: Download a static build from https://evermeet.cx/ffmpeg/
# Build and run
cargo run
# Run tests
cargo test
# Build release
cargo build --releaseNote: Pre-built releases include ffmpeg bundled. Building from source requires you to provide your own ffmpeg binary.
MP3 CD Burner is free and open source. If you find it useful, consider sponsoring the project on GitHub.
This project is licensed under the MIT License - see the LICENSE file for details.
