Add a watermark to a PDF
Before that draft leaves your hands, stamp it — a watermark doesn’t touch your content, it just lays a faint diagonal line of text over each page so whoever opens it knows what they’re holding. compress cat tiles a 45° watermark across every page of your PDF in the browser; the file is never uploaded.
Before that draft leaves your hands, stamp it — a watermark doesn’t touch your content, it just lays a faint diagonal line of text over each page so whoever opens it knows what they’re holding.
Chinese and any Unicode text are supported. Watermarks are tiled diagonally across every page. Runs locally, no upload.
How to add watermark
- 1Select a single PDF file.
- 2Type your watermark text (Chinese and any Unicode text are supported).
- 3Click “Add watermark & download” to save the result.
Why use compress cat's Add watermark?
- The watermark is an overlay, not an edit. It floats on top — your text, tables and signatures stay exactly as they were, and the original content sits intact underneath.
- Type whatever you need, in any script. “CONFIDENTIAL”, “DRAFT v3”, “机密 · 禁止外传”, “Internal use only” — Latin, CJK, numbers and symbols all render, tiled diagonally across the page.
- Every page gets stamped in one pass. On a 40-page contract or bid, no page slips through unmarked — no gap for someone to lift a clean copy from the middle.
Frequently asked questions
Honestly, no. It’s built to label and warn, not to lock down — someone determined can still strip it with the right tool. To actually protect a file, pair it with encryption or permissions rather than leaning on the watermark alone.
The current version uses a fixed 45° tile in semi-transparent orange-red — visible without burying the text. Custom angle, color and single-spot placement are on the roadmap.
Turn it into an automated flow
Need to batch-process, or chain several steps? Use the workflow builder to combine compress, merge, rotate and watermark into a reusable pipeline.
Updated · compress cat team