Jack! The Knife supporta i seguenti formati audio.

Estrazione audio da CD:

• Audio Wave (wav)

• Mp3 (mp3)

• Ogg Vorbis (ogg)

• Monkey's Audio (ape)

• FLAC Audio (flac)

• WavPack (wv)

• TAK (tak)

• MusePack (mpc)

• True Audio (tta)

• MPEG-2 AAC (aac)

• OptimFROG (ofr)

• Windows Media Audio (wma)

In codifica da Audio Wave (PCM):

• Mp3 (mp3)

• Ogg Vorbis (ogg)

• Monkey's Audio (ape)

• FLAC Audio (flac)

• True Audio (tta)

• Windows Media Audio (wma)

• MusePack (mpc)

• MPEG 2 (aac)

• MPEG 4 (mp4,m4a)

In decodifica:

• Mp3 (mp3)

• Ogg Vorbis (ogg)

• Monkey's Audio (ape)

• FLAC Audio (flac)

• True Audio (tta)

• RK Audio (rka)

• MusePack (mpc)

• Lossless Audio (la)

• WavPack (wv)

• MPEG 2 (aac)

• MPEG 4 (mp4/m4a)

• Windows Media Audio (wma)