Step 1: Supply your MP3 files using the button above or by haul and lay.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Get your converted AAC files.
MP3 to AAC Conversion FAQ
Is the MP3 to AAC conversion reversible?
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You can convert the AAC back to MP3 on this site. If either format involved is lossy, the round-trip is not bit-perfect even though it is visually or audibly close.
What output quality should I expect from MP3 to AAC?
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Default settings target broadcast / web quality — visually identical to the source for most viewers. For archival use, pick the highest quality option in the converter settings.
Is converting MP3 to AAC a second round of lossy compression?
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Yes, and it is worth planning around. Both formats are lossy, so the AAC encoder is working from audio that has already been through one psychoacoustic pass, and its own decisions compound the first set. At 192 kbps or above the result is still transparent for most listening. If you have a lossless master anywhere, encoding the AAC from that instead avoids the double pass entirely. MP3 is lossy: a psychoacoustic model discards frequencies the ear is unlikely to notice, typically at 128 to 320 kbps. AAC is lossy but more efficient than MP3, and it handles up to 48 channels natively rather than being bolted onto a stereo design.
What exactly is an AAC file?
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A bare run of encoded audio frames with no container wrapped around them. That is why two AAC files can usually be joined by simply putting one after the other, and equally why everything beyond the audio itself — a length, a seek index, cover art — has to be bolted on as a convention rather than being part of the format, so a player often has to read the whole file to work out how long it is. It is about the simplest thing that can be called an audio file, which is exactly why it turns up inside other containers more often than on its own.
Is MP3 free to use and distribute?
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Yes, without conditions worth worrying about. The specification is public, anyone can implement an encoder or decoder without asking or paying, and nobody can change those terms later — which is why it turns up in open-source tooling, in game engines and anywhere a licence negotiation would have killed the project. Converting away from it does not undo that; the files you already have stay exactly as usable as they were.
Who defines AAC?
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A standards body rather than a company, which is most of the reason it is everywhere. AAC was specified through the international process that produces the MPEG standards, so broadcasters, phone manufacturers, browser vendors and streaming services all implemented the same document instead of licensing somebody's product. The practical consequence is boring and useful: an AAC made by one tool decodes identically in another, and there is no vendor whose support could be withdrawn. AAC is Advanced Audio Coding, standardised in 1997 as MPEG-2 Part 7 and designed explicitly to replace MP3.
Is there a file-size limit when converting MP3 to AAC?
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Free conversions have a size limit per file, set by the type of file, and the page tells you when a file is over it. A paid plan removes that limit, so much larger files can be converted.
Can I batch-convert several MP3 files to AAC at once?
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Several files in one job need a paid plan. Free use is one file per conversion, one conversion an hour. On a paid plan you can add several files to one job, then download each result on its own or all of them in one ZIP.
What happens to my MP3 files after the conversion?
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Uploaded files are processed on our own conversion servers, nobody looks at them, and they are not shared. The upload and the converted file are both deleted automatically about 24 hours after the conversion, which leaves time to download the result. See /privacy/ for the full policy.
What apps can play a AAC file?
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AAC plays in most music players, browsers, and media libraries. iTunes / Apple Music, VLC, Foobar2000, and phone media apps handle it natively.
Do I need to install software to convert MP3 to AAC?
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No. The converter runs entirely in your browser plus our cloud — no plugin, no install, no admin rights. It works on Windows, macOS, Linux, ChromeOS, iOS, and Android.
Do I need an account to convert MP3 to AAC?
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Yes. One conversion an hour is free, with no account needed, for a file within the free size limit. A paid plan removes the hourly limit and the size limit, and lets you add several files to one job.
