Hex Editor for Mac or Any Platform Actually - MacVim (Vim)

Here's how to use Vim as a handy HEX editor:

 

  1. Open the file in Vim.
  2. Run the command to convert

    :% ! xxd</li>

  3. Edit all you need (i to get into insert edit mode)
  4. Once done, run to convert back

    :% ! xxd -r</li>

  5. Save (it's :wq)
  6. </ol>