Why run all four

No single reverse image search engine indexes the whole web. TinEye is built to find exact copies and trace an image back to its earliest known appearance — useful for spotting stolen photos or verifying a source. Google Lens and Bing lean on object/scene recognition, so they're better at "what is this" than "where else does this exact photo appear." Yandex often surfaces faces and regional content the other three miss. If you actually need an answer — not just the first result — check more than one. For the deeper mechanics and platform-specific tricks, see reverse image search on Google, Facebook & Pinterest and reverse video search.