How to use it
- Choose the PDF. Its page count appears under the name.
- Pick Text and type the words, or pick Picture and choose a logo as a PNG, JPG, WebP or GIF file.
- Set the size, the opacity and the angle, and choose One line in the middle or Repeated over the page.
- Leave Pages empty to mark every page, or type pages such as 1-3, 8. Click Add watermark, then Download.
Which letters the watermark can use
A text watermark uses Helvetica for the letters that font writes: digits, English letters and Western European letters such as Ç, Ö and Ü. Any other letter, such as Turkish ş, ğ, ı and İ, or Cyrillic, Chinese, Japanese, Devanagari or Arabic, is drawn as a picture of the text in the same colour, size and place, so the watermark looks the same in every language.
Layers and quality
The watermark is drawn over each page with the opacity you choose, and the pages underneath are copied unchanged. A tiled text is limited to 600 copies on one page, so a very small text is spaced further apart than its size. A picture is converted to PNG in your browser, which keeps its transparent areas.
Example: a DRAFT mark on a contract
Type DRAFT, keep the size at 48 points, set the opacity to 25 percent and the angle to 45, and choose One line in the middle. Each page gets a light grey DRAFT across its centre.
The contract's text stays readable underneath, and the mark is clearly a draft.
Frequently asked questions
Can I remove the watermark later?
Not with this tool. The watermark becomes part of the new file, so keep your original PDF and add the mark only to a copy.
Can I write ş, ğ or Cyrillic text in the watermark?
Yes. A letter the standard font cannot write is drawn as a picture of the text, in the colour and size you chose, so a Turkish, Russian or Chinese watermark looks the same as an English one.
Does the watermark change the text on the page?
No. The mark is added over the page and the text underneath is not changed, although a high opacity can make the text harder to read.
Which picture formats can I use for a logo?
PNG, JPG, WebP and GIF files work. A picture is converted to PNG in your browser, which keeps the transparent areas of a PNG, WebP or GIF logo, so the background does not cover the page.
Are my files uploaded anywhere?
No. Your browser reads the PDF and the picture, marks the pages and saves the new file on your own device. Nothing is sent to our server.
Sources
- pdf-lib, the open-source library that draws the watermark
- Windows-1252, the character set the standard PDF fonts write
Figures and text last checked on Tuesday, November 10, 2026.