MP3 to AAC converter

Convert MP3 to AAC in your browser. A more efficient codec — though converting an existing MP3 cannot recover what it already lost.

Runs on your deviceFree, unlimited

Drop files here

Accepts .mp3 · Up to 20 files at a time · up to 1.4 GB each "Upload" and "download" here mean your browser reading a file from this device and writing one back to it. Nothing is sent to a server — open your browser's network panel and watch: no request carries your file.

Audio quality

FAQ

Will the AAC sound better than my MP3?

No. It is a second lossy pass on audio the MP3 already reduced. AAC is the better codec, but it cannot restore detail that is no longer in the file.

Then when is this worth doing?

When a device or pipeline needs AAC, or when you want a smaller file — AAC degrades more gracefully than MP3 at low bitrates, so shrinking via AAC beats shrinking via MP3.

What bitrate should I choose?

Do not exceed the source. If the MP3 is 192 kbps, encoding AAC at 192 is safe and at 160 is usually indistinguishable. Going to 320 only makes the file bigger.

Should I get AAC or M4A?

M4A in almost every case — it is AAC in a container that supports tags and reliable seeking. Bare .aac is for technical pipelines.

Are the tags kept?

Tags in the MP3 are carried over unless you turn on "Remove metadata". Cover art does not always survive, since the formats store images differently.

Is it really free?

Yes — every conversion on this site, with no account, no watermark and no daily cap. The work happens on your own device, so there is no server bill for us to pass on to you.

Do I need to install anything?

No. It runs in any modern browser, on Windows, macOS, Linux, Android and iOS. There is nothing to download and nothing to sign up for, and once the page has loaded it keeps working with the network switched off.

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