Free PDF Watermark Tool
Upload your PDF and a logo or image, then drag to position and resize the watermark. Visual contact sheet shows all pages live. Download with original quality preserved — 100% private, runs in your browser.
Related Free PDF Tools
Professional Watermarking in Your Browser
Everything you need to stamp, brand, and protect PDF documents — no software, no account, no upload.
Any Image Format
Upload PNG, JPG, WebP, SVG, GIF, BMP, or AVIF as your watermark. All formats are automatically converted to the optimal format for embedding.
Drag to Position
Click and drag the watermark anywhere on the page preview. Position it precisely in any corner, centred, or wherever your brand guidelines require.
Drag Corner to Resize
Drag the corner handle to scale the watermark up or down. Aspect ratio is always preserved so your logo never looks stretched or distorted.
Opacity Control
Dial the opacity from fully opaque down to a subtle ghost watermark. Find the perfect balance between brand visibility and content readability.
Visual Contact Sheet
See all pages as thumbnails with the watermark overlaid in real time. Double-click any page to open a full-size preview modal to verify placement.
Selective Page Apply
Apply the watermark to all pages at once or pick individual pages. Cover pages, blank pages, and back matter can all be excluded.
Quality-Preserving Export
The output PDF uses pdf-lib to embed the image directly. Text stays selectable, links work, and original quality is fully preserved — no rasterisation.
100% Private & Local
Everything runs inside your browser. Your PDF and your watermark image never leave your device. No server upload, no cloud processing, no data stored.
Who Uses PDF Watermarking?
From protecting creative work to professional brand stamping, watermarks serve dozens of industries.
Brand Protection
Stamp client-facing documents, reports, and proposals with your logo to maintain brand presence across every page.
Confidential Marking
Add a "Confidential" or "Draft" stamp image to sensitive documents before sharing internally or with external parties.
Photography Portfolios
Protect PDF photo portfolios with a semi-transparent copyright logo that deters unauthorised reproduction.
Legal & Compliance
Stamp court filings, contracts, and legal briefs with firm logos or approval marks for professional presentation.
Frequently Asked Questions
Which image formats can I use as a watermark?
You can upload PNG, JPG/JPEG, WebP, GIF, BMP, SVG, and AVIF files. All formats are converted to PNG via an HTML5 canvas before embedding, so transparency is fully supported. PNG files with transparent backgrounds work best for logo watermarks.
Does the watermark preserve PDF text and links?
Yes. The tool uses pdf-lib to copy pages from your original document and then draws the watermark image on top. Text remains selectable and searchable, hyperlinks continue to work, and the original visual quality is completely unchanged. This is different from tools that rasterise the whole PDF.
How do I position the watermark precisely?
Drag the watermark image in the editor panel on the left. It snaps to the page boundaries so it cannot be dragged outside the page area. For fine control, you can make small drag movements — even one pixel of movement on the preview corresponds to a tiny fraction of the page.
Can I apply the watermark to only some pages?
Yes. Switch the Apply To toggle from "All pages" to "Selected pages". In that mode, each thumbnail in the contact sheet shows a checkbox. Click thumbnails to select or deselect individual pages. Only the checked pages will have the watermark in the downloaded PDF.
What opacity should I use for a background watermark?
For a diagonal "Confidential" or "Draft" stamp that sits behind content, 15-25% opacity works well. For a corner logo that needs to be clearly visible but not distract, 50-70% is a good range. For a fully opaque stamp on a blank area of the page, 100% is appropriate.
Is my PDF or watermark image uploaded anywhere?
No. Everything runs locally inside your browser tab using PDF.js for rendering and pdf-lib for generation. Neither your PDF nor your image file is transmitted to any server. You could disconnect from the internet after the page loads and the tool would continue to work perfectly.
Why does the watermark position look different in the downloaded PDF?
PDF coordinates have the origin at the bottom-left with Y increasing upward, while screen coordinates have the origin at the top-left with Y increasing downward. The tool automatically converts between these coordinate systems, so the visual position in the preview should match the output exactly.
Can I use a transparent PNG logo as a watermark?
Yes, and it produces the best results. Upload your logo as a PNG with a transparent background and set the opacity to suit your needs. The transparency in the image is preserved so only your actual logo pixels appear — no white box around it.
The Complete Guide to PDF Watermarking
Watermarking PDF documents is one of the most common tasks in professional document management. Whether you are protecting a photography portfolio, branding client deliverables with a company logo, marking draft versions for internal review, or stamping contracts with an approval seal, having a reliable watermarking tool is essential. Our free PDF watermark tool puts a complete watermarking workflow inside your browser tab — no software download, no account registration, and no file upload to any server.
Why Image Watermarks Are More Effective Than Text
Text-based watermarks, while convenient, have limitations. They are language-specific, lack visual brand identity, and cannot convey complexity — a logo contains shapes, colours, and typography that a simple text string cannot replicate. Image watermarks allow you to embed your actual brand assets: transparent PNG logos, official seals, signature images, or custom "Confidential" graphics created in your design tool.
Our tool accepts all common image formats including PNG (with full transparency support), JPG, WebP, SVG, GIF, and BMP. All formats are internally converted to PNG using an HTML5 canvas, which preserves transparency and produces optimal quality for embedding into PDF pages.
Visual Positioning: The Right Way to Place Watermarks
Guessing coordinates or entering pixel values is error-prone and wastes time. Our editor shows a live preview of the actual PDF page with the watermark overlaid at its current position and size. Drag the watermark to any location and see exactly how it sits relative to the page content. The contact sheet on the right updates in real time, showing all pages simultaneously so you can verify the watermark does not obscure important content on any page.
The aspect ratio of your watermark image is always preserved during resizing. Dragging the corner handle scales the image proportionally — your logo will never appear stretched or squashed regardless of how large or small you make it.
Selective Page Watermarking
Not every page in a document needs a watermark. Cover pages designed with your branding may not need an additional logo. Back matter, appendices, or blank pages can be excluded. Our selective page mode shows checkboxes on each thumbnail in the contact sheet. You choose exactly which pages receive the watermark, and the download reflects only your selections.
This is particularly useful for multi-section documents where the first few pages are heavily designed cover material and the remaining pages are standard formatted content that benefits from a corner logo watermark.
Quality Preservation: No Rasterisation
Many online watermark tools work by converting every PDF page to a JPEG or PNG image, drawing the watermark on top, and reassembling the images into a new PDF. This approach destroys text selectability, makes the document unsearchable, bloats the file size, and introduces visible compression artefacts around text characters.
Our tool uses pdf-lib to copy the original page objects directly — preserving all text layers, vector graphics, fonts, and embedded links — and then draws the watermark image on top as an additional graphics layer. The result is a PDF that maintains all the functionality of the original while adding the watermark cleanly on top.
Privacy and Security of Your Documents
Watermarking often involves sensitive documents — confidential contracts, proprietary research, client deliverables. Uploading these to cloud services creates genuine risk. Our tool runs entirely in your browser using client-side JavaScript. PDF.js renders page thumbnails locally. pdf-lib processes and generates the output locally. Your files are never transmitted anywhere. The tool works even without an internet connection after the initial page load.