Watermark PDF (image)

Scale sets the image size as a percentage of the page's longest dimension, from 5 to 100 per cent, with the aspect ratio locked so nothing is stretched. A wide logo is fitted by its width and a tall one by its height, which keeps a mixed set of pages looking consistent. Placement is anchored rather than free: the five chips drop the image into a corner or the middle, and the four corner options hold a 36-point margin from the visible page edge. There is no drag-to-position and, unlike the text watermark, no rotation control at all. Everything is measured against the page as a reader sees it, so rotated and landscape pages receive a correctly oriented stamp instead of one tipped onto its side.

JPG and PNG are the two accepted formats, and anything else is refused with a clear message rather than silently mangled — so SVG, WebP, HEIC, GIF and BMP need converting first. PNG transparency is preserved and combined with the slider: an alpha value of 50 per cent in the file and an opacity setting of 40 per cent multiply together, which is how a cut-out logo stays cut out. JPEG has no alpha channel at all, so a JPG logo always brings its background rectangle along with it; re-save it as a PNG if that background should disappear. JPEGs carrying an EXIF orientation flag are straightened before embedding, so a photo that looks upright in your file manager will not arrive rotated in the PDF.

Every page of the document receives the watermark — this tool has no page range, no first-page-only setting, and no way to repeat the image within a single page. Two routes get around that. To brand only part of a file, cut it with Split PDF, watermark the section that needs it, and reassemble with Merge PDF. To place the same logo twice on a page, run the tool once, drop the downloaded result back in, and stamp it again with a different position chip — the second image draws over the first without disturbing it. If what you actually want is a full page of branding rather than a mark, Overlay PDF stamps an entire PDF page instead of an image and does offer per-page scope.

The picture is embedded in the PDF and drawn into every page's content stream, so it cannot be toggled off in a viewer and it prints along with the document. It is still not a security measure. Somebody with a PDF editor can select the image object and delete it, and anyone determined can rasterise or re-photograph the page. There is no hidden marking either — nothing is buried in the file to trace a leaked copy back to a recipient. Use image watermarks for the honest purposes: showing ownership, marking a proof, making it obvious that a document is a sample. Keep the unstamped original, since the tool only adds and cannot remove an existing mark. To control who may open or change a file, encrypt it instead.

Neither file is uploaded — both stay on your device for the entire job. The PDF and the image are read straight from disk by the browser, the logo is decoded in the page to build the live preview, it is embedded into the document locally, and the stamped copy is written to your downloads with a -watermarked name. A company logo is rarely a secret, but the documents you stamp with one usually are: pricing sheets, client reports, signed agreements. None of it travels anywhere. The image also stays selected between runs, so you can drop one PDF after another over the dropzone and work through a whole batch without re-picking the logo or touching the network at all.

There is no paid plan, no signup and no per-file quota: the opacity slider, the full 5-to-100 per cent scale range and all five positions work straight away. The real constraint is your hardware rather than a licence, because the document and the image are both held in memory while the stamp is applied — a very large PDF on a phone is slower than the same job on a laptop, and the status line reports its progress page by page as it goes. The output carries your logo and nothing else: PDFChamp adds no second watermark of its own, no footer credit and no metadata line, so the stamped file is ready to send exactly as it comes out.