Add Watermark to PDF Free Online

Add text or image watermarks to any PDF online for free. Control opacity, angle, and position. No signup required. Private browser-based processing.

About Watermark PDF

Watermark PDF stamps your documents with custom text or image overlays — diagonal "CONFIDENTIAL" banners, company logos, draft notices, page numbers baked into the background — directly in your browser via pdf-lib without uploading the file anywhere. Text watermarks support full font, size, color, and opacity control, with four placement presets (diagonal, horizontal, header, footer) plus free-position drag. Image watermarks accept PNG (transparent background supported) and scale-to-fit or fixed-dimension placement anywhere on the page.

Most watermarking tools only do text. This tool handles both text and PNG image watermarks, applies them to all pages or a custom page range, and supports tiled watermarks — repeating the mark across the entire page in a grid pattern, the format used in legal discovery and confidential financial reports. Opacity from 5% to 100% lets you make watermarks subtle (barely visible ghost text) or bold (solid stamp). Hex color input means corporate brand colors like #003087 are exact, not approximated.

How We Compare

Compared to desktop alternatives like Adobe Acrobat Pro (starting at $19.99/month), Smallpdf ($12/month for unlimited), or iLovePDF ($9/month Premium), PDF AI Tools delivers comparable quality at $0 for the core feature set. We skip the subscription friction by processing most operations directly in your browser with WebAssembly — no server infrastructure costs to pass on to users. Our AI features (summarization, chat, OCR) use a pay-as-you-go backend that keeps your total cost well under $5/month even for power users.

How to Use Add Watermark to PDF Free Online

Step 1: Drop your PDF into the drop zone. The tool renders a full preview of the first page.
Step 2: Choose Text or Image watermark mode. For text, type your message and adjust font, size, color, and opacity. For image, upload a PNG.
Step 3: Pick a placement preset or drag the watermark on the preview to fine-tune its position. Enable Tiled mode for grid repetition.
Step 4: Set the page range: all pages, odd, even, or a custom range. Preview other pages by clicking the page thumbnail strip.
Step 5: Click Apply Watermark. pdf-lib stamps every selected page with your configured overlay. Download the stamped PDF.

Why Choose PDF AI Tools

We've built PDF AI Tools to replace expensive desktop software like Adobe Acrobat for 95% of common document workflows — at zero cost to you. Unlike competitors who gate features behind paywalls, add watermarks, or limit file sizes, our tools are genuinely free and genuinely unlimited. Your privacy matters: files processed client-side in your browser never touch our servers, and even AI-powered features use encrypted, auto-deleting processing pipelines.

Key Features

Text watermarks with full typography control — font, size (8-120pt), color (hex picker), opacity (5-100%), bold and italic
PNG image watermarks with transparent background support — scale, position, and opacity independently
Four placement presets — diagonal, horizontal, header, footer — plus free-position drag on the preview
Tiled mode — repeat the watermark in a grid across the entire page (standard for confidential legal documents)
Page range targeting — apply to all pages, odd/even only, or a custom range like 2-5, 8
Live preview updates with every setting change — see exactly what prints before downloading
Batch page application — one-click apply to every page in multi-page documents
Runs in browser via pdf-lib — document never uploads, private by design

Frequently Asked Questions

Can I remove a watermark that was added by this tool?

If you created the PDF and added the watermark using this tool, you can re-process the original (unwatermarked) file. This tool cannot remove watermarks from PDFs where you don't have the original — those are baked into the page content stream and cannot be cleanly reversed without the source file.

Does transparent PNG work for logo watermarks?

Yes. Upload a PNG with a transparent background and the tool places just the logo pixels without any white rectangle around them. JPEG uploads will have a white rectangle since JPEG has no transparency channel — use PNG for logo marks.

What is tiled mode and when should I use it?

Tiled mode repeats the watermark in a regular grid across the entire page — useful for confidential documents in legal discovery, draft versions of financial statements, and any document where you want the watermark to appear regardless of how the page is cropped or screenshotted.

Can I add different watermarks to different page ranges?

In the current tool, one watermark configuration applies to the selected page range. For different watermarks on different sections (e.g., DRAFT on pages 1-3, CONFIDENTIAL on pages 4-10), run the tool twice: once on the full PDF for each range, then merge the resulting segments.

What font options are available for text watermarks?

Helvetica, Times New Roman, Courier, Arial, and Georgia — all embed cleanly via pdf-lib without requiring font uploads. If your brand uses a custom font, use the image watermark mode instead: render your text in your brand font elsewhere, export as a transparent PNG, and upload that.