Convert MP3 to AAC Online Free
Convert your .mp3 files to .aac format. Free, fast, and processed entirely in your browser — your files never leave your device.
What is MP3?
MPEG Audio Layer 3 (.mp3) — MP3 is the most widely used audio format. It uses lossy compression to reduce file size while maintaining acceptable sound quality, making it ideal for music streaming and portable devices.
What is AAC?
Advanced Audio Coding (.aac) — AAC is the successor to MP3, offering better sound quality at similar bitrates. It is the default audio format for Apple devices, YouTube, and many streaming services.
MP3 vs AAC
| Feature | MP3 | AAC |
|---|---|---|
| Full Name | MPEG Audio Layer 3 | Advanced Audio Coding |
| Compression | Lossy | Lossy |
| Typical Bitrate | 128-320 kbps | 128-256 kbps |
| Best For | Music playback, podcasts, sharing audio files | Apple devices, streaming services, mobile audio |
| File Extension | .mp3 | .aac |
Frequently Asked Questions
Is converting MP3 to AAC free?
Yes, completely free. The conversion runs entirely in your browser using WebAssembly — your files never leave your device and no sign-up is required.
Will I lose audio quality converting MP3 to AAC?
Both MP3 and AAC use lossy compression. There may be a slight quality loss from re-encoding. If possible, convert from the original lossless source.
What is the maximum file size?
You can convert audio files up to 100MB. Since the conversion happens in your browser, processing speed depends on your device's performance.
Is my audio file uploaded to a server?
No. All format conversion is processed locally in your browser using FFmpeg WebAssembly. Your files never leave your device, ensuring complete privacy.