Many users are looking for a way to extract / convert WhatsApp chat history from .crypt12 backups and save them for example as MS Word document. Unfortunately, that's not done as a crypt to docx conversion (aka WhatsApp to Word) and no converter exists for this.
Nevertheless, you can achieve this with a workaround, but doing so requires two things. First, you will have to convert crypt12 to crypt and once you have the .crypt file you will have to use WhatCrypt Tools to export the message history as HTML. This format is widely accepted in word processors so making a Word document (.docx file) should be no problem.Open CRYPT12 file Open DOCX file
Online service for WhatsApp databases