How to convert MP3 to AAC
- 1
Upload your file
Drag and drop a file or click to select one. Keep this page open while the file uploads and converts.
- 2
Convert MP3 to AAC
NexMedia converts MP3 to AAC on its own servers. Processing time depends on the file size and how busy the queue is.
- 3
Download the converted file
When the conversion finishes, the download appears on this page. Your converted file is kept for 2 hours, then deleted.
About MP3
MP3 (MPEG-1 Audio Layer III) is a lossy audio format from the early 1990s. It removes the sound listeners are least likely to notice, typically at 128 to 320 kbit/s.
It plays on virtually every device and app, which makes it the default for music files, podcasts and audiobooks.
MP3 tops out at 320 kbit/s and two channels, and every re-encode removes a little more detail.
Convert MP3 to AAC online free, no account required — AAC is the lossy audio codec that succeeded MP3.
Change MP3 to AAC without losing quality — convert MP3 to AAC free in your browser.
Why does my MP3 sound muffled compared to the CD? The format discards frequencies the encoder deems inaudible, and a low bitrate throws away even more — re-encoding cannot bring them back.
About AAC
AAC (Advanced Audio Coding) is the lossy audio codec standardised in MPEG-2 and MPEG-4 as the successor to MP3; at the same bitrate it generally sounds better than MP3.
It is the audio in most MP4 videos, in Apple Music and on YouTube; a .aac file is a bare AAC stream without a container.
A bare .aac stream has only limited room for tags and cover art, so music players usually expect AAC inside an M4A file.
Why convert music to AAC instead of MP3? At the same bitrate AAC sounds better, and every modern phone, computer and streaming service decodes it.
What changes when you convert MP3 to AAC
- The audio is decoded and re-encoded as AAC at the default settings, so the result is close to the MP3 but not bit-identical.
- MP3 and AAC are both lossy formats, so this conversion adds a second round of lossy compression; keep the original MP3 if you may need the best quality later.
Settings you can change
Before you convert MP3 to AAC, you can adjust: Audio codec, Rate control, Audio bitrate, Quality (VBR), Sample rate, Channels, Normalize loudness, Trim start, Trim duration, and Keep tags.
Limits
Each plan sets a maximum file size and a number of conversions per day, and video and audio files also have a maximum length. Guests can convert files up to 100 megabytes and 5 per day; a free account raises this to 500 megabytes and 25 per day; paid plans go up to 100 gigabytes.
Your converted AAC file is kept for 2 hours, then deleted.
MP3 to AAC: questions and answers
Does converting MP3 to AAC reduce quality?
The audio is decoded and re-encoded as AAC at the default settings, so the result is close to the MP3 but not bit-identical. MP3 and AAC are both lossy formats, so this conversion adds a second round of lossy compression; keep the original MP3 if you may need the best quality later.
What is the difference between MP3 and AAC?
MP3 is a universally supported lossy audio format. AAC is the lossy audio codec that succeeded MP3.
Can I change the settings when converting MP3 to AAC?
Before you convert MP3 to AAC, you can adjust: Audio codec, Rate control, Audio bitrate, Quality (VBR), Sample rate, Channels, Normalize loudness, Trim start, Trim duration, and Keep tags.
Do I need an account to convert MP3 to AAC?
No. You can convert MP3 to AAC without an account; signing in raises the file-size and daily limits.
How long is my converted AAC file kept?
The AAC file you convert from MP3 is kept for 2 hours, then deleted automatically.
My MP3 is already lossy — does the AAC lose even more?
MP3 and AAC are both lossy formats, so this conversion adds a second round of lossy compression; keep the original MP3 if you may need the best quality later.
When I convert MP3 to AAC, is the audio re-encoded?
The audio is decoded and re-encoded as AAC at the default settings, so the result is close to the MP3 but not bit-identical.