md5 decoding. How they do it?

Question

i thought, that it is impossible to decode md5 hashes, but i found tools, which decode them here. but i have no idea, how they do it in such a short period of time(it takes

Answer 1

In general, this is still computationally intractable. However, rainbow tables assist in locating known pre-images. It will only work when the pre-image is based on common strings (e.g. dictionary words) and a salt isn't used. That's what they mean by "This tool searches multiple databases."