now, the site recommends Saucenao which can search files across furaffinity, deviantart, twitter (Only up to a certain point) and pixiv, Google Lens which is quite awful a good number of times, Kheina which handles the same websites as Saucenao and the last 2 are offsite search, on Inkbunny and Derpibooru. Out of these none of them support reddit, Google does to an extent, but is mediocre at its job.
Karmadecay is an image search engine that crawls through images found on reddit, more folk needs to know this tool.