How can I batch convert HEIC to JPG without losing quality?

I often need to bulk convert HEIC photos to JPG format when using my iPhone. I found a simple trick to send the photos to myself directly by email. This method is super convenient and does not require installing any additional software.

It is also very straightforward to use: I just need to select the HEIC photos I want to convert in the album, then click the share button like sharing anything, and select the email app. In the email writing interface, after I add the photos, the iPhone will automatically prompt me if I want to convert HEIC to JPEG format and send them. I choose "yes", set the email address to my own, and send it. Not long after, the email arrived in my inbox, and when I opened it, I saw that the photos were already in JPEG format.

The advantage of this method is that it is simple to operate, and there is no need to worry about the quality of the pictures, because the quality is basically the same during the conversion process. Of course, this method is more suitable for converting a few pictures occasionally. If it is hundreds or thousands of HEIC pictures, you may need to consider other more automated batch processing methods.