uploading duplicates

i just went through my image folder trimming it from 170000 files in 1 folder down to 5000, so i can open stuff up now.

i have no idea what is already on this site, and what was never here before. but i do know that 99.9% of the images i have never came from here directly.

do i have to search images to try to find what i have to offer before i upload, because only being able to search 2 tags at once, while doable, will defiantly be a long process. or is there some kind of script to try to catch any dups that i can see. like a hash or something?

http://danbooru.iqdb.hanyuu.net/

You can use http://danbooru.iqdb.org/ or run a tag search for md5:<md5 hash> (without the angle brackets).

Use IQDB that Evangeline linked. 100% hash matches will fail to upload, redirecting you to the image that is already up instead.

Note that you can also access the IQDB directly from the danbooru upload page, after entering your URL source or local filename source, by clicking the "Find similar" button instead of "Upload".