If the watermark is located in the far corner (top-left, bottom-right), you don't need to "remove" it; you need to cut it out . However, normal cropping ruins the video ratio (making it square or weird).
The keyword phrase reflects high user demand for zero-cost, web-based tools that claim to erase watermarks from video content. However, a critical distinction exists between legitimate watermark removal (from one’s own content) and copyright circumvention (removing ownership marks from third-party content). No reputable “exclusive” free online service can remove all watermarks from all videos without quality loss or legal risk. remove watermark from video online free exclusive