Upload a OGG file and get a AAC back. No signup, no watermark, no limit on how many.
OGG here means Vorbis audio in an Ogg container — a patent-free lossy codec that generally beats MP3 at the same bitrate.
Where you run into it: Game audio, Wikipedia and Wikimedia files, Spotify's streaming internals, Linux desktops.
What it costs you: Technical merit never bought it consumer support: plenty of car stereos and older phones simply do not list it.
AAC is MP3's designated successor and wins at low bitrates by a clear margin. A bare .aac file is the raw ADTS stream rather than the .m4a container most software expects.
Where you run into it: YouTube and streaming audio tracks, broadcast, anything that came out of a device rather than a music shop.
What it costs you: The naked .aac extension confuses a surprising amount of software, which is the usual reason people convert it.
This is a transcode between two lossy formats, so it is a second generation: OGG already discarded detail to get small, and AAC now encodes what is left and discards a little more. On a 320 kbps source you are unlikely to hear it. On something already thin — a voice note, a 96 kbps download — you may. Convert from the best copy you have, never from a copy of a copy.
Yes, entirely, and there is no cap on how many files you convert. No account, no watermark, no trial.
A little, in principle. OGG is already a lossy format and AAC is another one, so the audio is encoded a second time and a small amount more is discarded. From a good source it is very hard to hear; from an already-thin file it can be audible. Always convert from the best copy you have.
Roughly comparable, depending on the quality you pick. At the same bitrate the two files land within a few percent of each other; drop the bitrate and the AAC gets proportionally smaller.
Yes — AAC is one of the formats this converter writes, so the reverse page exists at /aac-to-ogg/. Remember that going back and forth between two lossy formats degrades the audio a little each time.
The file is uploaded to do the conversion — nothing here runs in your browser — and both your upload and the converted result are deleted the moment the file is sent back. Nothing is stored and nothing is logged beyond the request itself.