How to watermark a PDF
- Drop a PDF on the box above or click Choose a PDF. A preview of the first page appears on the right.
- Choose the type. For Text, write the words (for example CONFIDENTIAL or DRAFT), then pick the size, colour and bold. For Image, add a logo or stamp as a PNG or JPG and set its width.
- Set the position: one of nine places on the page, or Repeat across the page to tile the mark. Set the angle (45 gives the classic diagonal) and the opacity.
- To mark only some pages, type them in the Pages box, such as
1-3, 5. Leave it empty to mark every page. - Check the preview, click Add watermark and download
yourfile-watermarked.pdf. Your original is not changed.
Everything happens in your browser, so your document and your logo are never uploaded. There is no sign-up, watermark of ours or limit on the number of files.
Choosing opacity, size and angle
- Opacity. The mark is drawn on top of the page, so keep it low enough to read through. 20–35% works for a large text watermark; a small logo in a corner can be stronger, around 60%.
- Size. A diagonal text watermark covers the page best at about 60–90 pt on an A4 page, depending on the length of the words. The preview shows exactly how it fits.
- Angle. 0 is horizontal. Positive angles turn the mark counter-clockwise, so 45 rises from the bottom left to the top right and -45 falls the other way.
- Colour. Gray is neutral on most pages; red signals a status such as DRAFT; blue suits a company mark.
Text, languages and logos
Plain English text uses a standard PDF font, so the file hardly grows. Words with accents or Vietnamese tone marks, such as "TÀI LIỆU MẬT" or "BẢN SAO", need a Unicode font: the tool then embeds a small part of Noto Sans, served from this site, so every viewer shows the letters correctly. A logo is best as a PNG with a transparent background; a JPG always has a rectangular background, which will show as a box unless the opacity is low. Pages that are rotated in the PDF are handled: the mark appears at the chosen position and angle as the page is displayed.
Worked example
You send a 15-page proposal to a client for review and want it to be clearly marked as a draft. Type DRAFT, choose red, size 110 pt, bold, angle 45, opacity 25% and position Centre. The preview shows a large diagonal red word behind the text. Save, and every page carries the mark while the text stays readable and selectable. Later, to add your company logo to just the first page, open the saved file, switch to Image, choose the logo at 20% width, position Top right, angle 0, opacity 80% and type 1 in the Pages box.
Good to know
- A watermark is a deterrent, not protection. Anyone with PDF editing software can remove or cover it. For sensitive documents use access control, not only a mark.
- The mark is on top of the page. If something must not be covered, move the mark to a corner or reduce its size.
- One mark per run. To add both text and a logo, run the tool twice using the saved file the second time.
- Password-protected PDFs have to be unlocked first.
Frequently asked questions
Is my PDF uploaded to a server?
No. The watermark is added in your browser and the new file is saved on your device. Nothing is uploaded.
Can I use my own logo or stamp?
Yes. On the Image tab add a PNG (best, because it keeps transparency) or a JPG, then set its width, opacity, angle and position. A transparent PNG blends into the page without a white box.
How do I make the watermark diagonal across the page?
Leave the position on Centre and set the angle to 45. For a pattern of repeated marks choose Repeat across the page. The preview on the right shows the result before you save.
Can I watermark only some pages?
Yes. Type the pages, for example 1-3, 5, 8-, in the Pages box. Leave it empty to mark every page.
Can the watermark be removed afterwards?
The mark is added as part of the page content, so it cannot be switched off in a viewer, but a determined person can still edit it out with PDF editing software. A watermark deters casual copying; it is not a security feature.