Decipher Online
Text / image watermark · clean rendering
Add a Watermark to PDF
Both text and image watermarks are supported: set font, size, colour, opacity and rotation for text; PNG / JPG images keep their transparency. Both can be centered or tiled over the page.
Click or drag PDF files here
PDF only, multiple files at once (max 20) · up to 200MB each · max 500 pages
Watermark tool unavailable:服务器未找到中文字体（simhei.ttf / msyh.ttf），无法生成水印
How to use
Upload PDF → set options → download: three steps
1
Upload the PDF
Click or drag files into the upload area, page count and size are detected automatically.
2
Set the options
Choose a text or image watermark, then set size, opacity and layout.
3
Download the result
Processing runs locally on the server, then you can download the new PDF right away.
FAQ
Which watermark types are supported?
Both text and image watermarks. Text uses the fonts installed on the server (Sans / Kai / Fangsong / Serif) so no boxes or garbled glyphs appear; images support PNG / JPG (up to 5MB), PNG transparency is kept and the size scales by page width percentage.
Can the watermark be removed?
The watermark is drawn on a separate layer above the content as a visible mark; to remove one, use our PDF Watermark Remover.
Centered vs tiled?
"Centered" puts one watermark in the middle of each page, good for marking ownership; "tiled" repeats it across the whole page, good against screenshots being shared.