Add a Watermark to Your PDF Privately, in Your Browser

Stamp CONFIDENTIAL, DRAFT, or any custom text across your PDF without uploading a single byte. Free, no signup, instant results.

Drop a PDF to watermark
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Your PDF never leaves your device. Watermarking runs 100% in your browser using PDF-LIB. Nothing is uploaded, nothing is logged.

How to Watermark a PDF

A watermark answers a question before anyone has to ask it: is this final, is this internal, can I share this? GoPDFConverter stamps your text across every page (or just the pages you choose) in a few seconds, directly in your browser, with no uploads, no installs, and no cost.

  1. Open the Watermark PDF tool and drop your file, or click Choose a PDF.
  2. Type your watermark text. "CONFIDENTIAL" is the default, but anything up to 60 characters works: DRAFT, SAMPLE, DO NOT COPY, your name, a copyright line.
  3. Pick a layout (diagonal, horizontal center, or tiled), an opacity, a font size, a color, and optionally a page range like 1-3,5.
  4. Click Add Watermark & Download to save the stamped PDF.

Why Watermark PDFs in Your Browser

Think about what people watermark: legal drafts, financial reports, unreleased designs, contracts marked internal-only. These are, almost by definition, the documents you least want sitting on someone else's server. Yet most online watermark tools ask you to upload exactly those files before they will stamp the word CONFIDENTIAL on them. The irony writes itself.

GoPDFConverter takes the opposite approach. The watermark is drawn onto your PDF by the open-source PDF-LIB library running inside your own browser tab. The file is read locally, modified locally, and saved locally. There is no upload step to worry about, no retention policy to read, and nothing to delete afterward, because nothing ever left your machine.

One honest note: a text watermark is a label and a deterrent, not a lock. Someone with PDF editing software can remove it. It works because it makes a document's status unmistakable and casual misuse awkward, not because it makes copying impossible.

Common Watermark Use Cases

Frequently Asked Questions About Watermarking PDFs

How do I add a watermark to a PDF?
Open your PDF in GoPDFConverter's Watermark tool, type the text you want stamped, pick a layout and opacity, then click Add Watermark & Download. The watermark is applied in your browser and the result downloads immediately.
Can I customize the watermark text, position, and opacity?
Yes. You can enter any text up to 60 characters, choose diagonal, horizontal center, or tiled layouts, set opacity from 15% to 75%, pick a font size, and choose gray, red, blue, or black.
Can I watermark only some pages of a PDF?
Yes. Enter a page range like 1-3,5 to stamp only those pages. Leave the range blank to watermark every page.
Is watermarking a PDF free?
Yes, completely free. GoPDFConverter has no accounts, no per-file charges, and no limits on how many PDFs you watermark.
Is my PDF uploaded when I watermark it?
No. The watermark is applied entirely in your browser using PDF-LIB, so the file never reaches a server. That matters here more than anywhere: documents that need a CONFIDENTIAL stamp are exactly the ones you should not be uploading to a third party.
Can a text watermark be removed later?
Yes, a determined person with PDF editing software can remove a text watermark, so treat it as a deterrent and a label rather than security. It clearly marks a document's status and discourages casual reuse, but it does not prevent copying. For real protection, control who receives the file.