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Add Watermark to PDF

Stamp text like CONFIDENTIAL or DRAFT across every PDF page. Set opacity, size and angle. Private.

Your files never leave your device

How to add watermark to pdf

  1. 1

    Choose your PDF files

    Click the upload area or drag files onto it. Nothing is uploaded — files are opened locally.

  2. 2

    Adjust the settings

    Pick watermark text, opacity, placement, and color, then press the convert button.

  3. 3

    Download the result

    Save each file individually or everything at once as a ZIP.

Mark documents as drafts, confidential or copies before sharing them, or brand a PDF with your company name. The watermark is drawn on every page with the transparency you choose.

Read the full guide with screenshots

What is PDF?

PDF (Portable Document Format) preserves a document’s layout on every device and operating system, which makes it the standard for sharing, printing and archiving.

Is it private?

Yes. Unlike upload-based converters, ZapMorph processes files inside your browser tab, so the file stays on your device. It is never transmitted, stored or logged — close the tab and it’s gone.

Frequently asked questions

Is the add watermark to pdf converter free?

Yes. Convert 1 file a day without an account, or 5 files a day with a free account. Pro removes all daily limits.

Are my files uploaded to a server?

No. The conversion runs entirely in your browser, so your files never leave your device. We only count how many files you convert — never their names or contents.

What is the maximum file size?

Up to 25 MB per file without an account, 50 MB with a free account, and 1 GB on Pro. Very large files also depend on your device’s memory.

Can I convert multiple PDF files at once?

Yes. Select several PDF files at once — up to 5 on the free plan or 50 on Pro — and download all results in a single ZIP.

Does it work on Mac, Windows, iPhone and Android?

Yes. It works in any modern browser — Chrome, Edge, Firefox and Safari — on desktop and mobile, with nothing to install.

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