What is PDF Watermark?
PDF Watermark adds diagonal text watermarks to every page of a PDF document. Mark documents as DRAFT, CONFIDENTIAL, SAMPLE, or any custom text with adjustable opacity and color.
Add a diagonal text watermark to every page of a PDF.
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Type any phrase: 'CONFIDENTIAL', 'DRAFT', a client name, or your watermark of choice. Multi-word phrases supported with sensible defaults — type and apply.
Watermark appears diagonally across each page for maximum visibility without obscuring the underlying text. The classic legal/draft document style, applied with one click.
Adjust opacity from subtle gray hint to bold colored stamp, and tune font size for the document's page dimensions. Match the watermark's intensity to its purpose.
Watermark applies uniformly across all pages — no per-page configuration needed. Run multiple PDFs through with the same setting for consistent batch branding.
Watermark text is added as a single overlay layer per page via pdf-lib. Hundreds of pages get watermarked in seconds — no per-page render wait.
Watermarking is done locally with pdf-lib. Sensitive prototypes, NDAs, and pre-publication documents never get uploaded — the watermark proves they shouldn't.
PDF Watermark adds diagonal text watermarks to every page of a PDF document. Mark documents as DRAFT, CONFIDENTIAL, SAMPLE, or any custom text with adjustable opacity and color.
Watermarks are applied entirely in your browser using pdf-lib.
or drag & drop files here
Processed locally — your data never leaves your device.