Adding a watermark to a PDF sounds simple — but most free tools either add a logo watermark, watermark only the first page, or require a server upload for processing.

Here's a tool that does it properly: text watermark, diagonal placement, adjustable opacity, applied to every page, runs entirely in your browser.

PDF Watermark Tool — free, no upload, all pages

When You Need a PDF Watermark

Draft documents. Mark working drafts as "DRAFT" so reviewers know the document isn't final. Prevents a draft from being forwarded or filed as the approved version.

Confidential reports. Add "CONFIDENTIAL" or "INTERNAL USE ONLY" to documents before sharing with external parties. Creates a clear record that the document was shared with that designation.

Client deliverables. Add your company name or website as a light watermark on design files, proposals, or reports before sending. It's subtle branding, not obtrusive.

Sample documents.…