PDF Watermark Tool
Stamp text or a logo across your PDF — diagonal CONFIDENTIAL stamps, page ranges, no signup.
Also known as: PDF stamp tool, Watermark PDF online, PDF branding tool
How it works
- 1Upload your PDF — the page count and a live preview of page 1 appear immediately.
- 2Choose text or logo watermark, and fill in your message or upload your logo.
- 3Set opacity, rotation, size, and color, then pick a position from the 3×3 grid.
- 4Choose whether to apply it to every page or a specific page range.
- 5Check the live preview, then watermark and download the finished PDF.
Why use PDF Watermark Tool
Page range control, not all-or-nothing
Watermark every page, or just the range you specify — useful when only part of a document needs marking.
Text or logo, same controls
Switch between a status stamp (CONFIDENTIAL, DRAFT) and a logo watermark without learning a different interface.
Classic diagonal stamp look by default
Defaults to a rotated, semi-transparent look matching the standard document-watermark convention, fully adjustable.
Live preview matches the real output
The preview renders your actual first page with the watermark composited on top — no separate mockup that can drift.
No page limit
Watermark PDFs of any length — processing time depends on your device, not a page cap.
Nothing uploaded
Every step runs locally in your browser using pdf.js and pdf-lib — your document never leaves your device.
Who uses PDF Watermark Tool
Marking a contract or proposal as a draft
Stamp "DRAFT" diagonally across every page before circulating a version that isn't final yet.
Protecting a confidential document before sharing
Add a "CONFIDENTIAL" watermark before sending a sensitive report or financial document externally.
Branding a proposal or report with your logo
Stamp your company logo across every page of a client-facing document instead of just the cover.
Watermarking only part of a longer document
Apply a stamp to just the pages still under review in a long contract, using the page-range control.
About PDF Watermark Tool
A document watermark does one of two jobs: it marks a document's status (DRAFT, CONFIDENTIAL, SAMPLE) or it brands it (a logo across every page of a proposal or report). This tool handles both from the same interface — switch between a text stamp and an uploaded logo, and every other control (opacity, rotation, position, page range) works identically for either.
Page range control matters more than it sounds like it would: watermarking a cover letter along with a 40-page contract, or wanting a "DRAFT" stamp only on the pages still being revised, are both real, common needs that an all-or-nothing tool can't handle. This tool defaults to every page but switches to a specific from/to range in two fields, the same simple pattern Sejda and iLovePDF use rather than a more complex comma-separated page-list syntax.
The rotation default is -30°, the same diagonal angle real "CONFIDENTIAL" rubber stamps and their digital equivalents have used for decades, because it reads clearly at a glance without covering the document's actual content edge-to-edge. It's a default, not a requirement — dial it back to 0° for a straight horizontal logo watermark, which is the more common convention for branding rather than status marking.
Everything — reading the PDF's page count, rendering the live preview, and baking the final watermark onto every targeted page — runs locally using pdf.js (for preview) and pdf-lib (for the actual output). Your PDF is never uploaded to a server at any point in the process.
PDF Watermark Tool vs. other options
How Open Tools Library compares to desktop software and other online tools.
| Feature | Open Tools Library | Desktop software | Other online tools |
|---|---|---|---|
| Price | Free, unlimited | Often a paid app | Often free with usage limits |
| Page range control | Yes, simple from/to range | Varies by app | Sometimes all-pages only |
| Text and logo watermark, one tool | Yes, same interface | Varies by app | Sometimes separate tools |
| Live preview matches export exactly | Yes — same rendering, no mockup drift | Varies by app | Rarely guaranteed |
| Account required | Never | Sometimes | Often required |
Pro tips
- The default -30° rotation and 40% opacity is the standard "CONFIDENTIAL" stamp look — increase opacity if the text needs to be more prominent.
- For a logo watermark, a PNG with a transparent background blends into page content far better than one with a solid background.
- Use the page-range option when only specific pages (like unsigned or still-draft pages) need a stamp, rather than the whole document.
- Check the live preview at full opacity first to confirm size and placement, then lower opacity to the final subtle level.
- A straight (0°) rotation reads better for logo branding; a diagonal angle reads better for status stamps like DRAFT or CONFIDENTIAL.
Technical specs
- Watermark types
- Custom text or an uploaded logo image
- Position control
- 3×3 grid: corners, edges, and center
- Page targeting
- All pages, or a specific from/to range
- Page limit
- None enforced (device memory dependent)
- Output format
- .pdf, same page count and size as the source
- Processing location
- 100% local, in your browser
Privacy & security
A contract or report worth watermarking is usually one you'd rather not route through a stranger's server first.
Every watermark is baked onto the PDF locally, using pdf-lib in your browser tab.
Your logo, if you upload one, is processed the same way: entirely on your device.
No account, email, or login required to watermark a document.
The original and watermarked PDF are never uploaded or stored anywhere but your device.
Frequently asked questions
Is this tool really free with no limits?
Yes — no page cap, no signup, and no watermark or branding of ours added to your document alongside your own mark.
Does this upload my PDF anywhere?
No — reading the PDF, rendering the preview, and generating the final watermarked file all happen locally in your browser. Nothing is sent to a server.
Can I watermark only some pages, not the whole document?
Yes — switch from "All pages" to "Page range" and set the start and end page numbers you want watermarked.
Can I use a logo instead of text?
Yes — upload a PNG logo (ideally with a transparent background) and it scales proportionally to a percentage of the page size you choose.
Will this work on a scanned or image-based PDF?
Yes — the watermark is drawn as a new layer on top of each page's existing content, so it works the same whether the underlying page is real text or a scanned image.
Troubleshooting
The watermark text looks cut off or runs off the page edge
Long text at a large font size can exceed the available width in corner positions. Shorten the text, reduce the font size, or use a center position, which has the most room.
The watermark didn't appear on all my pages
Check whether "Page range" is selected instead of "All pages" — if a custom range is set, only pages within that range get watermarked.
My logo watermark looks pixelated
This means the source logo file itself is low-resolution. Upload a higher-resolution version — the tool scales it down to fit, but can't add detail that isn't in the original.
Why is the watermark diagonal by default?
It's set to the -30° angle standard "CONFIDENTIAL"/"DRAFT" stamps use, since it reads clearly without covering page content edge-to-edge. Set rotation to 0° for a straight horizontal watermark instead.
Guides and articles about PDF Watermark Tool
Related searches
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