The way that I usually find full-resolution pictures seems to work about 75% of the time, but most of the time, it's those 25% of pictures that I can't find that I actually want. I've used:

• https://iqdb.harry.lu
• https://images.google.com
• https://images.yandex.com (which works most of the time)

And if all else fails, I try to use manual tags on e621. However, even with all that, I'm still coming up dry on most of the pictures that were somehow shrunk in a boo-boo I made when migrating my collection from a failing drive in my server to a USB SSD (don't ask).

I guess what I'm trying to ask is... is there another way I can utilize one of these tools to find these pictures, or is there another service I can push these pictures through to find them?

forum #249240

If filenames are original, those also can give information like artist, artworks name, timestamp and website of origin, one of the many reasons why I have listed URL formatting in here.