Audio format
What is a AAC file?
AAC is the compressed audio format behind iTunes, YouTube, and most streaming services — generally more efficient than MP3 at the same bitrate.
AAC (Advanced Audio Coding) was developed as the designated successor to MP3 under the MPEG standard, using newer compression techniques to squeeze out noticeably better sound quality at the same bitrate, or an equivalent quality at a smaller file size. Apple adopted it as the default format across iTunes and the iPhone early on, and it's since become the standard codec behind most video and streaming platforms as well, since it handles the low bitrates needed for streaming particularly well.
How to open a AAC file
AAC files open readily in Any modern media player, Any web browser, iTunes/Apple Music. For real editing rather than just viewing, reach for Audacity (free), Adobe Audition.
Strengths & limitations
Good for
- better quality-per-kilobit than MP3
- the default format across Apple's ecosystem
Watch out for
- slightly less universal hardware support than MP3, though still very broad
Convert AAC files
Orbfile can convert AAC both ways, entirely in your browser — pick a direction below:
Frequently asked questions
What does a AAC file contain?+
AAC is the compressed audio format behind iTunes, YouTube, and most streaming services — generally more efficient than MP3 at the same bitrate.
Can I convert AAC for free?+
Yes — Orbfile's audio converter handles AAC for free, with no file limit, watermark, or account, and it runs entirely in your browser.
Is converting a AAC file safe and private?+
Yes. Orbfile processes AAC files locally on your device using WebAssembly — nothing is uploaded to a server, so there's nothing to leak or store.
Who created the AAC format?+
AAC was developed by MPEG (Moving Picture Experts Group), first released around 1997.
Browse the full file format guide.