Add Watermark to PDF

Watermarks work best when they are obvious enough to notice but light enough to read through — around 15–25% opacity on a mid-grey is the usual sweet spot, and pure black at high opacity almost always makes the document unusable. Diagonal rotation of about 45 degrees is conventional because it crosses the text block, making the mark hard to crop away without destroying content. If your goal is deterring redistribution rather than marking status, tiling is significantly more effective than a single centred mark.

The text is drawn onto each page at a computed anchor point using the page’s own dimensions, rotated about that point and rendered with an alpha value equal to your opacity setting. Tiling repeats the same draw across a grid whose spacing is derived from the text width and font size.

This adds a text watermark only — image and logo watermarks are not supported. The mark is drawn as ordinary PDF text on top of the page, so it can be selected and, by anyone determined, removed with the right software. It is a visible ownership marker and a deterrent, not document security: use PDF permissions or encryption if you need to genuinely restrict a file.

Stamping “CONFIDENTIAL” at 48pt, 20% opacity and 45° rotation across a 10-page report places one diagonal grey mark in the centre of every page, still leaving the underlying text fully readable.

1. Choose your PDF file.
2. Type the watermark text and pick a colour.
3. Adjust size, opacity and rotation, and tick tiling if you want it repeated.
4. Download the watermarked copy — your original is untouched.

• Setting opacity so high the underlying text becomes hard to read.
• Using a single small corner mark that is trivially cropped out.
• Assuming a watermark prevents copying — it does not.
• Watermarking the only copy you have instead of working from a duplicate.

This tool stamps a text watermark across every page of a PDF — “CONFIDENTIAL”, “DRAFT”, a client name or a copyright line — with control over size, colour, opacity, rotation and position. Tick tiling to repeat the mark across the whole page instead of placing it once.

Anyone sharing draft documents, contracts, proposals or portfolios who wants ownership or status marked clearly.

• Your document never leaves your device — unlike every upload-based watermarker.
• Tiling mode covers the whole page, which is far harder to crop out.
• Full control of opacity and rotation, so the mark stays readable underneath.
• Applies to every page in one pass, however long the document.

• Marking a contract as DRAFT before it is signed.
• Adding a client name to a proposal you are sending out for review.
• Stamping CONFIDENTIAL on internal documents.
• Putting a copyright line across a portfolio or sample chapter.