I've created a executable jar file that I can customize for use on your computer. It's written in Java and implements the Jsoup Html parser. It's sort of like a bot or web-crawler (I guess?).

It can download all images associated with a tag, So artist, character, or something else, and a single image (if needed). However It is not perfect, so I wouldn't try to download a tag with 1000 pages associated with it.It can download, with fast enough internet speed, ~200 images associated with a tag in 3-4 minutes.

It has the ability to back-list tags, so you don't have to have save unwanted images on you computer. It also will write the image name, artist of image, and character tags to a txt file, for all images saved to your drive, that can be converted to a CSV file that you can store in a database or even run in Excel/libre. It won't (can't or I don't know how) download flash games/movies. It works fine with Windows and if needed I can get it to work with Ubuntu.

I have downloaded all of the files that I want right now and will spend most of my time sifting through Images I want and don't want. So I am willing to share my executable jar so you too can download images more quickly off of e621.

Send me a message if your interested so I can hard code some stuff (for your convenience) into the program and send it to you.