Add Watermark to PDF

No, the watermark here is text drawn in bold Helvetica, and there's no image upload. For placing a logo on photos, the Image Watermark tool handles pictures with its own position and opacity controls. On contracts and reports, a text stamp usually reads more clearly anyway.

Stay between 15 and 40 percent for documents people still need to read. The 30 percent default is a sensible anchor. Push toward 100 only for void stamps where obscuring the content is the point.

Every page, centered, at the same angle and size throughout. The note under the filename says so up front. If only certain pages need marking, split those out first, stamp them, and merge the file back together.

The 30 degree counterclockwise tilt crosses both text columns and white space, so the stamp stays visible regardless of layout, while a horizontal mark can vanish into a line of body text. You can drag rotation anywhere from -90 to 90 degrees.

No, it's communication. The text becomes part of the page content, but a determined person with an editor can strip it, and it doesn't encrypt anything. Treat it as a strong label, and reach for password protection when access control is the real goal.

Yes: no signup, no branding of ours on the output, no page limit inside the 100 MB cap. The only marks on the download are the ones you typed.

Fully client-side. The document loads into your browser's memory, pdf-lib draws the text, and the download is generated locally. Draft settlements and unfiled patents never touch a server.

Between 60 and 90 points works well on A4 and letter pages, large enough to register at a glance. Above 100 points a long word may run past the edges on portrait layouts, and the live preview will show that overflow before you commit.