How it works
The PDF Image Stamp tool embeds a PNG or JPG image — typically a logo, company seal, watermark image, or approval stamp graphic — onto every page of a PDF document. The image is positioned at one of five anchor points (four corners or center) with configurable width and opacity, and is rendered directly into the page content using pdf-lib's vector drawing layer.
Common use cases: a company adds its logo to every page of client-facing reports. A law firm stamps a red "VOID" graphic over superseded contracts. A photographer watermarks proof PDFs with a semi-transparent logo. An organization adds an official seal to credential certificates. A consultant marks every page of a proposal with a light-gray "CONFIDENTIAL" image overlay.
How to use it: 1. Upload your PDF. 2. Upload the stamp image (PNG supports transparency; JPEG does not — use PNG for logos with transparent backgrounds). 3. Choose the position (bottom-right for logos, center for watermarks, top-right for approval stamps). 4. Set the stamp width in PDF points (72pt = 1 inch). Height is calculated automatically from the image's aspect ratio. 5. Set opacity: 100% for fully opaque stamps; 30–60% for semi-transparent watermarks. 6. Click Add Image Stamp. Every page receives the stamp at the specified position.
PNG vs JPEG for stamps: PNG with a transparent background is strongly preferred for logos — JPEG images have a white background that will cover any content beneath the stamp area. Use JPEG only for full-page watermarks or cases where background coverage is acceptable.
Privacy: all embedding uses pdf-lib in the browser. Your images are never uploaded.
Frequently Asked Questions
- You uploaded a JPEG file, which does not support transparency. JPEG images always have a white or opaque background. Convert your logo to PNG format with a transparent background before uploading. PNG (Portable Network Graphics) supports an alpha channel that preserves transparent areas, so the stamp appears with only the logo visible — no white box around it.
- This tool stamps every page with the same image. For per-page image stamps, extract individual pages with the PDF Page Extractor, stamp each separately, and merge the results. For a single-page stamp (e.g., a signature page stamp), extract that page, stamp it, then merge it back.
- PDF points to inches: divide by 72. A 72pt stamp is 1 inch wide, 144pt is 2 inches, 216pt is 3 inches. For a logo that should appear at 2 inches wide, enter 144. For an A4 page (595pt wide), a 144pt logo at the bottom-right corner occupies about 24% of the page width — generally appropriate for a watermark or footer logo.
- Yes. The stamp is embedded as a vector image element in the PDF page content, not as a screen-only overlay. It will print at the same opacity you configured, on every printer that renders the page. Opacity of 30–50% is often ideal for watermarks that should be visible in print but not dominate the document.