Lee's Handy Dandy Alphamorphic / Digimorphic Calculator

Type text into the text area below, like

Will you be my Valentine?

and then click Convert to Digits.

  

Your entry evaluated to

Type encrypted text into the text area below, like

=+23+35+38+38+95+51+41+47+95+28+31+95+39+51+95+22+27+38+31+40+46+35+40+31+91

and then click Convert to Letters.

  

Your entry evaluated to

Note: an offline pair of executables that do what this does may be obtained here.