Add a text or image watermark with full control over opacity, position, size and rotation. Nothing leaves your device.
Add a text or image watermark to your photos entirely in the browser, no file ever leaves your device. Adjust opacity, choose your position (corner, center, tiled mosaic), and preview the result in real time before downloading.
Ideal for photographers and creators who want to brand their work before sharing online, without trusting a third-party server with their original high-resolution images.
No. Your image is processed by the HTML5 Canvas API in your browser tab, it is drawn onto a canvas and your text or logo is composited over it (drawImage), then exported with toBlob, and the result is offered as a local download. Nothing reaches Sunasty or any third party. Open your browser's DevTools, go to the Network tab and watch: no request carries your image.
Yes. Enable the tiling option and the watermark is repeated in a grid pattern across the entire image at the opacity you choose.
Any format your browser can decode, PNG (with transparency), JPEG, WebP, GIF. PNG with a transparent background works best so the watermark blends naturally.
Yes, once the page has loaded. Because the processing happens on your device, you can disconnect from the network and the tool keeps working. This is the clearest proof that your data never leaves your machine.
It is completely free and requires no sign-up. There are no watermarks, no daily limits and no tracking cookies needed to use the tool.