MP3 to AAC Converter
Drop an MP3 file, convert it to AAC right in your browser, and download the result — no upload, no account needed.
Use the MP3 to AAC Converter
MP3 to AAC Converter
Everything runs in your browser — your file is never uploaded.
AAC encoding not supported in this browser
Your browser's MediaRecorder does not support AAC output. Please use Chrome or Safari on Windows, macOS, or Android. Firefox does not currently support AAC encoding via MediaRecorder.
Encoding is captured in real time: a 10-minute track takes about 10 minutes after decoding.
MP3 vs. AAC
MP3
- Universal device support
- Widely supported in software
- Less efficient than AAC
- Older codec from the 1990s
AAC
- Better quality at lower bitrates
- Default for Apple, YouTube, streaming
- Smaller file size at equal quality
- Encoding requires hardware/browser support
Select an MP3 file to get started
Your file is never uploaded — conversion runs in your browser
Duration
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File Size
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Channels
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Decoding audio...
Conversion complete
How the Conversion Works
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1
Web Audio API decodes your MP3 file into raw PCM audio data in memory.
No upload required — all decoding happens locally.
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2
An AudioBufferSourceNode plays the decoded audio into a MediaStreamDestination.
This creates a live audio stream the browser can capture.
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3
MediaRecorder captures the stream at playback speed and encodes it to AAC.
A 10-minute track therefore takes about 10 minutes to capture.
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4
When encoding is complete, the output is packaged as a downloadable file.
MP4-contained AAC uses .m4a; raw AAC uses .aac.
Summary
Drop an MP3 file, convert it to AAC right in your browser, and download the result — no upload, no account needed.
How it works
- Drop your MP3 file onto the upload area or click to browse.
- The browser reads the file metadata: name, size, and duration.
- Click "Convert to AAC" — the Web Audio API decodes the MP3 to raw PCM audio.
- MediaRecorder captures the decoded audio in real time and encodes it using the browser's supported AAC MIME type.
- A download link appears automatically. MP4-contained AAC is saved as .m4a; raw AAC is saved as .aac.
Use cases
- Prepare audio files for iPhone, iPad, or macOS apps that prefer AAC.
- Reduce file size while maintaining audio quality for streaming or podcasting.
- Convert MP3 tracks to AAC for iTunes or Apple Music library import.
- Create AAC audio for video projects that require an mp4-compatible audio stream.
- Test AAC compatibility before publishing audio to platforms like YouTube.
- Convert personal music files to a more efficient format without uploading to a cloud service.