Step 1: Share your AAC files using the button above or by drag and drop.
Step 2: Click the 'Transform' button to start the transformation.
Step 3: Grab your converted MP4 files.
AAC to MP4 Transformation FAQ
Is the AAC to MP4 converter free?
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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.
How big an AAC file can I convert to MP4?
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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 convert many AAC files to MP4 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.
Does the AAC to MP4 converter work on phones and tablets?
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Yes — the UI is responsive and the conversion pipeline runs server-side, so mobile devices upload-then-download just like desktops. iOS and Android browser file pickers (camera roll, Files app) work end-to-end.
Which browsers does the converter support?
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Chrome, Firefox, Safari (15+), Edge, and Opera. The converter uses standard `<input type="file">` upload — no WebAssembly or PWA dependency — so even older browsers work to upload an AAC and download the MP4.
Are my AAC files kept private?
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Yes. Uploaded AAC files are processed on our own conversion servers, no person reviews them, and they are never shared. The upload and the converted MP4 are both deleted automatically about 24 hours after the conversion, which leaves time to download the result. See /privacy/ for the full policy. AAC sounds noticeably better than MP3 below 128 kbps and is the default audio track in MP4, YouTube, Apple Music and broadcast.
What if the MP4 download does not start automatically?
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Disable any pop-up blocker, then click the download button manually. The result link stays active for 24 hours, so if your network drops mid-download you can retry from the result page without re-uploading the AAC.
How long does AAC to MP4 conversion take?
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It depends on the size and length of the file. Small documents and images are usually ready quickly. Long videos take the longest, because most video conversions re-encode every frame. MP4 is the safest possible delivery target — every phone, browser, console, editor and Smart TV built in the last decade plays it without extra software. MP4 only supports one widely-honoured subtitle format (mov_text), and multi-track audio is unreliable outside desktop players.
Do I need to install software to convert AAC to MP4?
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No — the converter runs entirely in your browser plus our servers. No desktop install, no plugin, no browser extension. Just upload, wait briefly, download the MP4.
Can I convert AAC to MP4 without creating an account?
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Yes for one-off conversions. Sign up free for batch history, server-side file storage, and higher conversion limits. Premium adds parallel workers, bigger file caps, longer result retention, and no ads.
