Online PDF Watermark Tool
Add a tiled text watermark such as "CONFIDENTIAL" or "DRAFT" to every page of a PDF for free. Adjust font size, angle, opacity and color. Processed in your browser, no upload.
How to Use
Select file
Start process
Local processing
Download result
Complete PDF Watermark Guide
What the watermark tool does
The watermark tool repeats a text watermark across every page of your PDF — for example "CONFIDENTIAL", "DRAFT", "SAMPLE" or your company name. You can set the font size (20–100), angle (-90° to 90°), opacity (5–80%) and color; the default is light grey text (#888888, 15% opacity) at −45°. Non-Latin text such as Chinese and Japanese is supported, and you are warned before processing if a character is missing from the font. Everything runs in your browser, nothing is uploaded, and it is free with no sign-up (5MB per file on the free plan). Only text watermarks are supported; image or logo watermarks are not.
How to add a watermark
1) Open the watermark tool and choose a PDF. 2) Type the watermark text. 3) Adjust size, angle, opacity and color. 4) Click Add watermark and download the new PDF. Your original file is not changed.
Use cases and recommended settings
Confidential documents: "CONFIDENTIAL" at 15–25% opacity stays visible without hurting readability. Drafts for review: "DRAFT", optionally in light red. Samples and portfolios: your company name or URL at 30% or more makes reuse harder. Note that a watermark is text drawn on the page and can be removed with dedicated software; to stop people opening or copying the file, also use PDF Encrypt.
Processing Results
Technical Specifications
Feature Comparison
| Feature | Allin PDF | Other Tools |
|---|---|---|
| File upload | Not needed — applied in your browser | Many online tools upload files to their servers |
| Adjustable settings | Size, angle, opacity, color | Varies by tool |
| CJK text | Supported | Varies by tool |
Key Facts
Allin PDF adds a text watermark tiled across every page of a PDF; only text watermarks are supported.
Font size ranges from 20 to 100 (default 48), angle from −90° to 90° (default −45°), opacity from 5% to 80% (default 15%), and the color is adjustable (default #888888).
Allin PDF watermarks support Chinese, Japanese and Korean text and are applied in your browser with pdf-lib, so the file is never uploaded.
One PDF is processed at a time and saved with a _watermarked suffix; files can be up to 5 MB on the free plan and 50 MB on Pro, with no sign-up.
Privacy Protection
This tool processes your files in your browser: they are not uploaded to a server, and no sign-up or login is needed.
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FAQ
Is the PDF watermark tool free?
Yes. Adding a watermark is free with no sign-up and no daily limit. The free plan accepts PDFs up to 5MB; Pro raises this to 50MB.
What can I customize?
The watermark text, font size (20–100), angle (-90° to 90°), opacity (5–80%) and color. The text is repeated diagonally across every page.
Can I use Chinese, Japanese or Korean text?
Yes. A CJK font is loaded automatically when needed. If a character is not in the font, the tool lists it before processing so you can change the text.
Can I add an image or logo watermark?
Not at the moment. The tool adds text watermarks only. You can type your company name or website as the watermark text.
Is my PDF uploaded?
No. The watermark is added in your browser with pdf-lib, and your original file is not modified.
Process Documents Anywhere
Download the Allin PDF iOS app. Its local tools also work offline.