A watermark tells everyone who opens a PDF what it is: a draft that should not be signed, a confidential document that should not be forwarded, a sample that is not the paid version, or a file that belongs to your brand. This tool adds a text or image watermark to an existing PDF, on every page or only the pages you choose.
It runs in your browser with pdf-lib. Your PDF and your logo are never uploaded, and the preview is drawn from the same code that writes the final file.
How to add a watermark to a PDF
- Drop the PDF on the box at the top of this page, or click it and choose the file. A preview of page 1 appears beside the options (below them on a phone).
- Choose Text or Image or logo.
- For text, type the words, set the Font size in points, pick a Color and one of three bold fonts. For an image, click Choose PNG or JPG and set its Width as a percentage of the page width.
- Set the Opacity (25% is a good start) and the Rotation, from -90 to 90 degrees. 45 degrees gives the classic diagonal stamp.
- Choose a Layout: One stamp placed in one of nine positions, or Tiled across the page for a repeating pattern.
- Leave Pages empty for every page, or type a range such as
2-10. - Check the preview. The arrows under it step through the pages, and pages outside your range are labeled "no watermark".
- Click Add watermark and download the file, named after your original with
-watermarkedadded.
Text watermarks
Text watermarks are drawn as real text in Helvetica Bold, Times Bold or Courier Bold. They stay sharp at any zoom and add almost nothing to the file size. Common choices:
| Text | Typical settings | Used for |
|---|---|---|
| DRAFT | Gray, 90 pt, 20% opacity, 45°, center | Proposals, contracts and reports still under review |
| CONFIDENTIAL | Red, 60 pt, 25% opacity, 45°, center | Financials, HR documents, pricing sent to one partner |
| SAMPLE or PREVIEW | Gray, 28 pt, 20% opacity, 30°, tiled | Free previews of paid printables, templates and e-books |
| COPY | Black, 48 pt, 15% opacity, 0°, top right | Copies of originals kept on file |
| Prepared for Jane Smith | Gray, 14 pt, 30% opacity, 0°, bottom center | Personal copies that discourage forwarding |
The standard PDF fonts cover English and Western European letters. If you type text in another script, such as Arabic, Chinese, Hindi or Cyrillic, or include emoji, the tool draws the text into an image with your system font and places that instead. It looks the same, but that watermark cannot be searched or selected.
Logo and image watermarks
For a brand watermark, use a PNG with a transparent background. The transparent areas stay clear, so only the logo shows over the page. A JPG always brings its rectangle with it, which looks like a box sitting on the page; at low opacity it is less obvious, but PNG looks cleaner. WebP files also work and are converted to PNG first.
Image size is set as a percentage of the page width, so a 40% logo is 40% as wide as each page, whatever the page size. On a US Letter page that is 3.4 inches. The image's own proportions are kept. For sharp results, use an image at least as many pixels wide as it will appear at 150 DPI: 510 pixels for a 3.4 inch logo, more if the document will be printed.
Tip: if your logo exists only inside a PDF, turn it into a transparent PNG with PDF to PNG (crop the page around it first with Crop PDF), then use that PNG here.
Position, tiling and rotation
With One stamp, the nine-position grid places the watermark in a corner, along an edge or in the center. Edge and corner positions keep a small margin from the paper edge and take the rotation into account, so a rotated stamp in the top right corner stays fully on the page.
With Tiled across the page, the watermark repeats in staggered rows, like bricks, with gaps based on its size. Smaller text gives a denser pattern: 28 pt text tiles into a pattern that covers the whole page, while 90 pt text gives only a few large repeats. Tiling is the better choice for previews and samples, because a single stamp can be cropped out of a screenshot, while a tiled pattern covers every part of the page.
Rotation turns the watermark counterclockwise for positive angles, so 45 degrees runs from bottom left to top right. Negative angles run the other way. The tool also handles pages that are landscape or stored with a rotation setting: the watermark is placed and angled based on how the page appears in a viewer, so it looks the same on every page.
Worked examples
A confidential price list
A 6-page wholesale price list goes to one retailer. Type CONFIDENTIAL, red, 60 pt, opacity 25%, rotation 45°, center, all pages. On a Letter page the word runs across about half of the diagonal, and the prices underneath stay readable through the 25% red. Add a second line by running the file through again with "Prepared for Coastal Boutique" at 12 pt, bottom center, 0°.
A free preview of a paid printable
You sell a 30-page planner and give away a 5-page sample. Extract pages 1 to 5 with Extract PDF Pages, then watermark them with SAMPLE in gray, 28 pt, 20% opacity, 30°, tiled. The pattern covers each page, so the sample is clearly a sample even when printed. When you post those previews to Pinterest and Instagram, AM Jarvis Social Autopilot can schedule the posts for you, written by your own AI.
A logo on a client deliverable
An agency adds its logo to the bottom right of a 20-page audit. Choose Image, pick the transparent PNG logo, width 15%, opacity 80%, rotation 0°, bottom right, and type 2- in Pages so the cover stays clean. On a Letter page the logo is about 1.3 inches wide.
Choosing settings that stay readable
A watermark that makes the document hard to read defeats its purpose. A few rules of thumb from documents that work well:
- Big means faint. The more of the page a watermark covers, the lower its opacity should be. A center stamp at 90 pt works at 15 to 20%; a corner logo can be fully opaque.
- Gray is safest. Mid gray reads as "watermark" on any page. Red draws attention for CONFIDENTIAL, but at more than 30% it starts to fight with red text and charts.
- Angle it for text pages. A diagonal watermark crosses many lines a little, so no single line is hidden. A horizontal one across the middle can cover a whole line of text.
- Check the busiest page. Use the preview arrows to find the page with the smallest text or the darkest image, and judge the settings there, not on the cover.
- Print a test page. Opacity looks different on paper. If the file will be printed, print one page before sending the whole set.
Other ways to watermark a PDF
- In the source file: Word and Google Docs can add a watermark before you export to PDF. Word has it under Design > Watermark. This is a good route when you still have the original and want the watermark behind the text rather than on top of it.
- Adobe Acrobat: the paid Acrobat apps have a watermark feature with similar options. The free Acrobat Reader cannot add watermarks.
- Mac Preview: Preview has no watermark feature. A text box added with the markup tools is an annotation that anyone can delete with one click.
For a finished PDF from a client, supplier or scanner, a tool that stamps the existing file, like this one, is the quickest option.
How strong is a PDF watermark?
A watermark is a visible label, not protection. Because it is drawn on top of the page as normal PDF content, someone with a PDF editor can select it and delete it, just as they could edit any other text. It discourages casual copying and makes leaks traceable when each copy names its recipient, but it does not stop a determined person.
To make a watermark much harder to remove, flatten the watermarked file into images with the image option in Flatten PDF. The watermark then becomes part of each page picture. The cost is that text is no longer selectable or searchable and the file gets larger, so keep that for samples and previews rather than working documents.
Who watermarks PDFs
- Digital product sellers mark free samples of planners, worksheets, patterns and templates so previews cannot pass as the paid file.
- Agencies and freelancers stamp DRAFT on proposals and audits until the client approves, and add their logo to final deliverables.
- Wholesalers and brands label price lists and line sheets CONFIDENTIAL, often with the buyer's name, so a leaked copy is easy to trace.
- Photographers and designers send proofs with a tiled name or logo that stays on every part of the image.
- Offices mark copies, void documents and internal versions so the original stays clearly the original.
The common thread is a label that travels with the file. Whoever opens it, on whatever device, sees the same mark in the same place.
Troubleshooting
- The watermark hides the text underneath. Lower the opacity to 15 to 25%, or use a lighter color. The watermark sits on top of the page content, so opacity is what keeps the page readable.
- The logo has a white box around it. It is a JPG or a PNG without transparency. Export the logo as a transparent PNG from your design app.
- The logo looks blurry. The image has too few pixels for its size on the page. Use a larger image or a smaller width.
- The PDF will not open. If it is password protected or restricts editing, remove the password with Unlock PDF first (you need the password).
- A page has no watermark. Check the Pages box. The preview label shows "no watermark" for pages outside the range.
Privacy and limits
The tool is free, with no daily limit, no account and no watermark of its own. The PDF and the logo are processed in your browser and never uploaded. A tiled pattern adds up to a few hundred stamps per page, which keeps files small for text watermarks; image watermarks are stored once in the file and reused on every page, so even a 200-page document stays light.
Your original file is never changed. If the result is not quite right, adjust the settings and click Add watermark again; each run starts from the original PDF, so watermarks never stack up by accident.