Add Watermark to PDF

Why Documents Need Watermarks

A proposal sent to a prospect, an internal report shared with a contractor, a draft circulated for review — these are documents that need to communicate their status clearly on every single page, not just on a cover sheet that might get separated. A watermark printed diagonally across the page means that even if someone screenshots a single page or prints it without the cover, the handling requirement is unmistakable. Our free online PDF watermark tool lets you stamp any text on every page of a PDF in seconds, with full control over appearance — no desktop software, no upload to a cloud service.

Controlling the Appearance — Settings That Actually Matter

The live preview updates in real time as you adjust settings. Opacity is the most important control — 20–30% gives the classic semi-transparent watermark that is readable without obscuring the document content. At 80–100%, the watermark becomes a solid stamp, suitable for corner positions at smaller font sizes. Font size controls how dominant the text is: 48–60pt works well for diagonal watermarks across A4 or Letter pages; 14–18pt is appropriate for corner stamps. The Rotation slider (available in Diagonal mode) lets you set the exact angle — the traditional 45° diagonal is the default, but some organisations prefer shallower angles like 30°. Color is a full colour picker: red is traditional for CONFIDENTIAL stamps, grey for subtle branding, blue for draft markings.

Watermark Text That Communicates the Right Message

• CONFIDENTIAL: The most common watermark for business documents — signals restricted distribution to the intended recipients only
• DRAFT: Prevents a work-in-progress from being acted upon before final approval — once the document is finalised, add professional page numbers with our Page Numbers tool before distributing
• SAMPLE: Branded templates and proposals sent to prospects to prevent direct use without payment or agreement
• FOR INTERNAL USE ONLY: Clear instruction on documents that must not be shared outside the organisation
• DO NOT COPY: Legal and compliance documents where reproduction is controlled or prohibited
• Company or individual name: Text-based ownership branding on every page — for logo-based branding, use our Add Image to PDF tool to place a PNG logo instead

Content-Layer Watermark vs Annotation Watermark

There are two ways to add text to a PDF page: as an annotation object (like a sticky note layer) or as a content-layer element (drawn directly into the page description stream). Annotation watermarks can be hidden by recipients who know how to toggle the annotations panel in their PDF viewer. Our tool uses the content-layer approach exclusively — the watermark text is drawn as part of the page itself, at the same level as the original document content. This means it prints, displays in every viewer including mobile PDF readers, and cannot be switched off without a full PDF content editor.

Preparing the Document Before Watermarking

If you need to combine multiple files before watermarking, use our Merge PDF tool first to create a single document, then apply the watermark in one operation — this ensures consistent positioning across all pages. If the document has mixed portrait and landscape pages, the watermark is positioned relative to each page's own dimensions, so it will appear proportionally correct regardless of page orientation.

Sector-Specific Watermarking Requirements

• Legal practices: Privileged and confidential correspondence, court documents shared during discovery, client contracts in review
• Finance and accounting: Preliminary accounts, draft financial statements, internal budget reports shared before board approval
• Healthcare: Patient information shared for second opinions, medical reports in draft review phase
• Architecture and engineering: Preliminary design drawings, tender documents, conceptual plans shared before formal sign-off
• Publishing: Advance reading copies (ARCs), proof documents, manuscript drafts shared with reviewers before publication

Processed Entirely in Your Browser

All watermarking uses pdf-lib running locally in your browser tab. Your PDF file, its contents, and your watermark text are never transmitted to ToollyX servers or any third party. This is essential for applying watermarks to legally privileged documents, commercially sensitive reports and patient records that must not be processed on external servers.

✓Verified by ToollyX Team · Last updated June 2026