How to add a watermark to a PDF
A watermark is text or a logo layered across every page of a document — DRAFT, CONFIDENTIAL, a company name, or a copyright notice. It signals the document's status or ownership without interfering with the content underneath.
Text vs. image watermarks
A text watermark is the quickest: a word or short phrase, usually set at an angle across the page, in a light grey so the underlying text stays readable. CONFIDENTIAL and DRAFT are the classic uses, marking a document's status so no one mistakes a working copy for the final version.
An image watermark places a logo or graphic instead, which is the right choice for branding documents or asserting ownership of a design. Either way, the watermark applies to every page so the marking is consistent throughout.
Getting the opacity right
The single most important setting is opacity. Too solid and the watermark fights with the text; too faint and it is pointless. Aim for something clearly visible but light enough to read straight through — around 15-25% opacity works well for most documents. A diagonal angle also helps it read as a watermark rather than part of the content.
Applying the watermark in your browser means the document is never uploaded, and you download the watermarked copy while keeping your unmarked original.