pdfMB

Add watermark

Text or a logo across your pages, with a live preview. The original text stays selectable, and your file stays on this device.

  • No uploadYour file stays on this device.
  • Your original stays as it isYou download a new copy. Your file is never changed.
  • Free, no sign-upNo account and no daily limit.

What happens to your file

Everything below happens inside your browser, on your own device. The PDF is never uploaded, so nobody else, including us, can see it.

  1. Your browser reads the PDF into memory. Nothing is sent over the network.
  2. The watermark is added to each chosen page as real text, or as your image. The page’s own text, pictures and links are not redrawn, so you can still select, search and copy them.
  3. English letters use Helvetica Bold, which every PDF reader has. Thai, Vietnamese and other accented text uses the Sarabun font, and only the letters you use are stored in the file. Scripts the font does not cover, such as Chinese or Arabic, are added as a picture instead.
  4. Opacity is saved as a transparency setting, so the page shows through the watermark in every reader.
  5. Size and position are worked out from how each page looks on screen, so turned and cropped pages get the watermark in the right place. Text that would run off the page is made smaller automatically.
  6. The preview is drawn on your device with pdf.js and uses the same layout as the saved file.
In short
  1. Choose a PDF
  2. Type text or choose a logo
  3. Adjust it and pick pages
  4. Press “Add watermark” and download

How to add a watermark to a PDF

  1. Choose a PDF. A large preview of the first page appears with a grey diagonal watermark on it.
  2. Type your text or tap a quick-fill button, or switch to Image and choose a logo.
  3. Adjust the size, colour, opacity, angle and position. Use the arrows to check other pages.
  4. Pick the pages: all, odd, even, first, last, or the page numbers you type.
  5. Press “Add watermark” and download the new file.

When people use it

Confidential drafts

Mark contracts, budgets and reports as confidential or as a draft before they go round for review.

Copies you hand out

Stamp “COPY” or “Do not share” on documents you send to an agent, a landlord or a supplier.

Your logo on documents

Put a faint logo behind the pages of a quote, a portfolio or course notes.

Thai documents

Thai text such as “ลับ” or “สำเนา” comes out with vowels and tone marks in the right place, and can be copied as text.

What it can’t do

  • Anyone with PDF editing software can remove a watermark added as its own layer, from this tool or any other. For an ID copy, use the ID copy watermark, which burns the mark into the page picture.
  • A watermark behind the content is hidden wherever the page has pictures or a white background, as most scans do.
  • Chinese, Japanese, Korean, Arabic, Hebrew, Hindi and other scripts the font does not cover are added as a picture, which can’t be selected as text.
  • Readers built on pdf.js, such as Firefox, may copy the Thai vowel “ำ” as two characters. Chrome, Adobe Reader and others copy it correctly.
  • Watermarks already in the file are not removed.
  • Password-protected PDFs, and PDFs whose owner has blocked editing, can’t be opened.
  • A digital signature in the PDF is no longer valid after any change, including a watermark.

Questions about watermarks

Can someone remove the watermark?

Yes, with PDF editing software, because it is added as its own layer. That is true of most PDF watermarks. If the copy must not be cleaned, for example an ID card copy, use the ID copy watermark, which burns the text into the page picture.

Can I still select and search the text in my PDF?

Yes. The pages are not turned into pictures. Only the watermark is added, and your own text stays as it was.

Can I use my logo?

Yes. Switch to Image and choose a PNG or JPG. A PNG with a transparent background looks best. Set the opacity low so the page stays readable.

Can I watermark only some pages?

Yes. Choose odd, even, first or last pages, or type page numbers such as 1-3, 8. The counter shows how many pages will get the watermark.

Does it work in Thai?

Yes. Thai text is stored with the Sarabun font, with vowels and tone marks in the right place, and it copies as Thai text.

Does it lower the quality?

No. The pages are not redrawn or compressed. Only the watermark is added, so the file grows only slightly.