Convert MP3 to AAC.
Turn an MP3 into AAC audio for apps, devices and workflows that expect AAC.
When AAC is required
Some streaming tools, broadcast systems, video editors and older iPods and car stereos want AAC rather than MP3. This conversion covers those cases.
Quality
AAC is efficient, so it holds quality well, but the source is already an MP3. Always convert from the best original you have, and keep it.
Size change
The AAC is usually similar in size to the MP3, or a little smaller.
How it works
- 01
Upload your MP3
Drop a file or pick one from your device. Private by default.
- 02
Encode with ffmpeg
ffmpeg decodes the MP3 and encodes AAC audio.
- 03
Download
Grab your AAC.
Real AAC encoding with ffmpeg
Keeps the original sample rate and channels
Private uploads, auto-deleted after 1 hour
No watermark, no signup to try
Open-source ffmpeg engine
MP3 to AAC: re-encoded
AAC is a compressed, lossy audio format, so this re-encodes the sound and the file gets smaller. Every lossy re-encode sheds a little quality, so convert from the best source you have rather than chaining conversions.
Need more than a conversion?
Send your audio or video to TranscriptAI to generate a transcript, summary, structured notes, flashcards, quiz questions or action items: automatically.
Common questions
Is it free?+
Yes. Convert MP3 to AAC free. No signup and no watermark. Free covers 10 server conversions a day, up to 100 MB a file. Pro removes the daily limit and raises the file limit to 2 GB.
Is my file private?+
Your file is uploaded to a private bucket, converted on our own engine, and auto-deleted after 1 hour. It is never sent to a third-party converter.
Will it sound better than the MP3?+
No. Converting between two lossy formats cannot restore what the MP3 encoder removed, and it adds a second round of compression. Convert when a destination requires AAC, not to improve quality.
AAC or M4A?+
A .aac file is raw AAC audio. An .m4a is AAC inside an MP4 container, which also holds tags and cover art. Most Apple apps prefer M4A; MP3 to M4A gives you that.
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