knowable vs readable

knowable

adj
  • Capable of being known, understood or comprehended. 

readable

adj
  • legible, possible to read or at least decipher 

  • which can be read—i.e. accessed or played—by a certain technical type of device 

  • enjoyable to read, of an acceptable stylistic quality or at least functionally composed 

How often have the words knowable and readable occurred in a corpus of books? (source: Google Ngram Viewer )