seeable vs viewable

seeable

adj

  • Able to be seen; visible. 

noun

  • That which is to be seen. 

viewable

adj

  • Able to be seen; visible. 

  • Able to be rendered correctly by a particular browser. 

  • Able to be viewed. 

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