The free sub/idx to srt converter is designed to convert one sub/idx file at the same time.
However, if you have many sub/idx files, converting them one by one is an annoying and long process.
The sub/idx batch tool solves the problem of converting many sub/idx files at the same time. But, due to the heavy load this tool puts on the server, it is not free to use. You need to buy tokens to use the tool, you can buy 50 batch tokens for €4,95. You get a few free batch tokens when you register your account to try out the tool.
The sub/idx batch tool makes it easy to convert many sub/idx files at the same time. It works roughly as follows: