Free PDF Watermark Tool — Add Text Watermark to PDF Online

PDF Watermark Guide

Why Add a Watermark to a PDF?

Watermarks protect documents before distribution — marking drafts as DRAFT, confidential reports as CONFIDENTIAL, or review copies as DO NOT COPY. They signal ownership, status, and intent without altering the underlying content. Unlike image editing, PDF watermarks are applied as a text layer, keeping the file size small and the original layout intact.

• Diagonal support: 45° and -45° diagonal watermarks are the industry standard — harder to crop out and visually unmistakable on every page.
• Opacity control: Adjust from 5% (nearly invisible, barely-there) to 80% (bold, prominent). Most use cases sit around 25–35%.
• 100% private: Your PDF never leaves your device — all processing runs in the browser using pdf-lib.
• No account required: Open the page, upload, configure, download. No email, no registration.
• No vendor branding: The downloaded PDF contains only your watermark — no QuickTooly logos or overlays added.

How to Add a Watermark to a PDF

Adding a watermark takes under a minute. Three steps from upload to download.

Step 1: Upload Your PDF

Drag and drop your PDF into the upload area, or click "Select PDF File" to browse. Files up to 50 MB are supported. Nothing is sent to any server — all processing runs locally in your browser.

Step 2: Configure the Watermark

Type your watermark text or pick a quick preset (CONFIDENTIAL, DRAFT, COPY, DO NOT COPY). Choose a rotation — 45° diagonal is the standard for official documents — then adjust opacity, font size, and color to match your needs.

Step 3: Download the Watermarked PDF

Click "Add Watermark & Download." The tool stamps your text onto every page and saves the result instantly. The original PDF is not modified — you get a new watermarked copy ready to share or archive.

Key Features of This PDF Watermark Tool

Diagonal Watermarks — 45° and -45° Rotation

Diagonal watermarks are the professional standard because they cross the entire page, making them impossible to cleanly crop out. This tool supports both 45° (bottom-left to top-right) and -45° (top-left to bottom-right) angles, as well as horizontal and vertical orientations for less intrusive use cases like report headers.

Opacity Control — From Subtle to Bold

A simple slider lets you fine-tune how prominent the watermark appears. Set it to 10–20% for a light background watermark that doesn't obscure the content, or 50–80% for a bold stamp on review copies. Most legal and corporate use cases work best between 25% and 40%.

100% Private — Runs Entirely in Your Browser

The entire watermarking process — loading the PDF, drawing text on each page, and rebuilding the file — runs inside your browser using pdf-lib. Your document is never transmitted to any server. Safe for confidential contracts, personnel files, financial reports, and medical records.

Custom Text — Any Watermark You Need

Quick-pick presets cover the most common use cases — CONFIDENTIAL, DRAFT, COPY, DO NOT COPY — but you can type any text up to 80 characters. Use your company name, a case reference number, a date, or any label that suits your workflow.

No Adobe Acrobat Required — Works on Any Device

PDF watermarking used to require Adobe Acrobat Pro, a paid desktop application. This tool runs entirely in your browser with no software to install — open the page on any computer, phone, or tablet and watermark your PDF in seconds. No subscription, no trial, no account.

Frequently Asked Questions

How do I add a watermark to a PDF without Adobe?

Adobe Acrobat Pro can add watermarks, but it costs a subscription and requires a desktop install. This tool does the same thing for free, directly in your browser — no download, no account, no Adobe required. Upload your PDF, type your watermark text, and download the result in under a minute.

Can I add a logo or image watermark to a PDF?

This tool adds text watermarks only — CONFIDENTIAL, DRAFT, your company name, or any custom phrase up to 80 characters. If you need an image or logo watermark, you'll need a PDF editing tool that supports image layers, such as Adobe Acrobat.

Can I add a diagonal watermark to a PDF for free?

Yes — this tool is completely free with no account required. Upload your PDF, choose the 45° diagonal rotation, set your text and opacity, and download the watermarked file in seconds.

Will the watermark be on every page?

Yes. The tool stamps the watermark text onto every page of the PDF automatically. Multi-page documents are fully supported — each page receives an identical centered watermark.

Is it safe to watermark confidential documents online?

Completely safe. Your PDF is processed entirely in your browser using client-side JavaScript and pdf-lib. It is never uploaded to any server. Once you close the tab, nothing is retained — making this tool safe for payslips, contracts, medical records, and legal documents.

Can I remove a watermark added by this tool?

Watermarks added by this tool are stamped as a PDF content stream layer — they are part of the page content. They cannot be removed without specialized PDF editing software. Keep the original unwatermarked file if you need it later.

What opacity should I use for a CONFIDENTIAL watermark?

For most professional use cases, 25–35% opacity is ideal — visible enough to clearly mark the document, but not so heavy that it obscures the text or images underneath. For review copies you want to clearly flag, use 40–60%.

Does this work on scanned PDFs?

Yes. The tool works on any PDF regardless of how it was created — scanned documents, digitally generated files, and exported reports are all supported. The watermark is drawn on top of the existing page content, including scanned images.

Can I watermark a PDF on my phone?

Yes. The tool runs entirely in the browser and works on any device — iPhone (Safari), Android (Chrome), iPad, Mac, or Windows PC. No app installation required. Open the page, upload your PDF from Files or Google Drive, configure the watermark, and download the result directly to your device.

Related Tools

Looking for more PDF tools? Browse all PDF utilities on QuickTooly, use the PDF Metadata Remover to strip hidden author and edit history before sharing, or the PDF Compressor to reduce the file size after watermarking.