Image Watermarker

An image watermarker overlays a mark - usually a logo, a signature or a handle - onto a photograph so that the image carries its source with it. It is the oldest attribution mechanism on the internet and still the most effective one, because unlike metadata it survives a screenshot, a repost and a crop through most social platforms. Photographers use it to keep credit attached to work that will be reshared, and businesses use it so a product image stays branded wherever it ends up.

Two decisions do most of the work: where the mark sits and how visible it is. A small mark in a corner at moderate opacity is the polite option - it credits without competing with the picture, and it is what most people want. A tiled mark repeated across the whole frame at low opacity is the defensive option: much harder to crop or paint out, and correspondingly more intrusive. This tool does both, along with size, opacity, margin, rotation and tile spacing, and it sizes the mark against the shorter side of the image rather than the width, so the same settings look right on a portrait and on a panorama instead of tiny on one and enormous on the other.

Be clear about what a watermark is for. It deters casual reuse and it makes attribution travel with the file. It is not copy protection: anyone determined can crop it out, clone it away, or run an inpainting model over it, and no visible mark changes that. What it does change is the effort required, which is enough to stop the great majority of unattributed reposts. Everything here runs on a canvas in your browser - neither the photograph nor the watermark is uploaded, and the output keeps the original resolution untouched.