Base64 is gelica 'twegengestaðoled-to-bōcstafas' rūndihtenda gesetnessa hēap se speleð twegengestaðoled gecyþnessa in ASCII strengstihtunge be hie onwendunge in a wyrtrum-64 spelunge. Se word 'Base64' is of þǣm Nīwenglisce gereorde and cymþ of MIME gewyrðe oferfarerūndihte.
Ælc Base64 getalustæf spelaþ efne siexe gecyþnessa anfingeras.