Watermark Image stamps text or a logo onto a photo, either in a single spot or tiled repeatedly across the whole image, to mark ownership or discourage unauthorized reuse before you share it.
A low-opacity watermark is meant to be unobtrusive for marking ownership, not tamper-proof; a determined person with image-editing skills could still remove it, especially from a single corner placement. Tiling it across the whole image, or increasing opacity, makes it significantly harder to clean up without noticeably degrading the image.
Yes. Switch to the Logo tab and upload a PNG or JPG. A PNG with a transparent background usually looks best, since it blends into the photo rather than covering it with a solid rectangle.
No. The watermark is composited directly onto the image using the browser's own canvas, and nothing is sent to a server.