Can I use my own custom text for the watermark?

Yes — enter any text you like, such as "DRAFT," "CONFIDENTIAL," your name, or a company label.

Does the watermark appear on every page?

Yes — the same watermark is stamped across every page of the document in one operation.

Can I control how visible the watermark is?

Yes — adjust the opacity to make it more subtle or more prominent, and the font size to control how large it appears.

Do I need an app from the App Store?

No — it works directly in Safari or Chrome on iPhone, with nothing to install from the App Store.

Can I use the Files app or Photos to upload?

Yes — use the Share Sheet from either app to send a file straight into the upload dialog.

Security

Watermark PDF on iPhone

iOS doesn't come with a full PDF toolkit built in beyond very basic viewing, and installing a dedicated app just for an occasional task is overkill for most people. My PDF works directly in Safari or Chrome on iPhone, using the same Files app or Photos share sheet you already know.

Use the Watermark PDF Tool

No registration required
Files deleted automatically
Works in any browser

Why This Matters

What Is a PDF Watermark Tool?

A PDF watermark tool stamps custom text diagonally across every page of a document, at an adjustable size and transparency, without permanently altering the underlying content beneath it. The result is a document that visibly carries a label — "DRAFT," "CONFIDENTIAL," a company name — on every single page, in a way that is difficult to simply crop or edit out.

Step by Step

How to Watermark PDF on iPhone

Upload Your PDF

Drag in the document you want to watermark, or click to browse and select it. On iPhone, tap the upload area and choose Photos or Files, or use the Share Sheet from either app.

Enter Your Watermark Text

Type the text you want stamped across every page, and adjust its font size and opacity.

Click Add Watermark

Our server stamps the watermark diagonally across every page, typically within seconds.

Download the Watermarked File

Save your PDF with the watermark applied consistently throughout.

Recommended Tool: Watermark PDF

Stamp text or a logo across every page of a PDF.

Open Watermark PDF

Get Better Results

Tips

Lower the Opacity for Legibility — A lighter, more transparent watermark keeps the underlying content fully readable while still being clearly visible.
Increase Font Size for Emphasis — If the goal is to make the watermark impossible to miss, use a larger font size alongside a higher opacity.
Use the Share Sheet from Photos or Files to send an image or document straight into the browser's upload dialog.
iPhone screenshots and photos are usually already in JPG or PNG format, so they work directly with no extra conversion step first.

Avoid These

Common Mistakes

Uploading a file that is already password-protected without unlocking it first — most operations require an unencrypted starting file.
Assuming a converted or compressed file replaces the need for the original — keep your source file until you have confirmed the result looks right.
Not checking the 50 MB upload size limit before starting, then wondering why a very large scan fails to upload.
Installing a separate PDF app from the App Store for a single occasional task instead of using the browser already open.