Watermark PDF

Why Add Watermarks to PDFs?

Watermarking PDF documents is essential for protecting intellectual property, marking document status, and maintaining professional standards. Whether you're sharing a draft proposal, distributing confidential reports, or branding documents with your company logo, watermarks communicate important information at a glance.

According to Grand View Research (2024), the global digital watermarking market is valued at $1.45 billion and projected to reach $3.80 billion by 2033. The Center for Strategic and International Studies estimates that global intellectual property theft costs $600 billion annually.

Common scenarios where you need to watermark PDFs:

• Draft documents: Mark proposals, contracts, and reports as "DRAFT" so recipients know the content isn't final.
• Confidential materials: Stamp sensitive financial reports, legal documents, or HR materials with "CONFIDENTIAL" to deter unauthorized sharing.
• Company branding: Add your company logo as a subtle background watermark to white papers, presentations, and client deliverables.
• Copyright protection: Mark photography portfolios, design mockups, and creative work with ownership information.
• Sample documents: Label product demos, trial reports, or evaluation copies with "SAMPLE" to distinguish them from paid versions.

Text vs. Image Watermarks

PDFJolt supports two types of watermarks, each suited to different needs:

Text Watermarks

Type any text — "DRAFT", "CONFIDENTIAL", "DO NOT COPY", your company name, a date, or any custom message. Customize the font size (20-120pt), color (red, blue, gray, black, green), opacity (5-100%), and rotation angle (-90° to 90°). Text watermarks are lightweight and don't increase file size significantly.

Image Watermarks

Upload a PNG or JPG image — your company logo, a stamp graphic, or a signature. The image is automatically scaled to fit within 40% of the page size while maintaining its aspect ratio. Adjust opacity and position to create a subtle background effect or a prominent overlay.

Watermark Position Options

PDFJolt offers seven position options to place your watermark exactly where you need it:

• Center: Places the watermark at the center of each page — the most common position for "DRAFT" or "CONFIDENTIAL" stamps.
• Diagonal: Centers the watermark with rotation for a classic angled stamp effect.
• Tiled: Repeats the watermark in a grid pattern across the entire page — ideal for maximum coverage and harder to remove.
• Corner positions: Top-left, top-right, bottom-left, bottom-right — suitable for logos, page numbers, or subtle branding.

How PDFJolt Watermarks PDFs Differently

Most online watermark tools like iLovePDF, Sejda, and PDF Candy require uploading your document to their servers. Your confidential draft, logo file, and document content all travel across the internet. PDFJolt processes everything in your browser:

• No upload required. Your PDF never leaves your device.
• Live preview. See exactly how your watermark looks before applying it — no waiting for server processing.
• Instant application. Watermarks are applied in seconds, even on large documents.
• Works offline. Once loaded, PDFJolt works without an internet connection.

PDFJolt vs. Other PDF Watermark Tools

Feature	PDFJolt	iLovePDF	Sejda	Adobe Acrobat
Price	Free (2/day)	$7/mo	$7.50/mo	$22.99/mo
Privacy	Client-side (no upload)	Cloud upload	Cloud upload	Cloud/Desktop
Text watermark	Yes (custom text, color, size)	Yes	Yes	Yes
Image watermark	Yes (PNG/JPG)	No	Yes	Yes
Live preview	Yes	No	No	Yes (desktop)
Tiled watermark	Yes	No	Yes	Yes
Works offline	Yes	No	No	Desktop only

Technical Details

PDFJolt's watermark engine is built on pdf-lib, a robust open-source JavaScript library. When you apply a watermark, the engine:

1. Loads your PDF document in the browser's memory
2. Embeds the Helvetica font (for text watermarks) or your uploaded image
3. Iterates through each page and draws the watermark using drawText() or drawImage()
4. For tiled mode, calculates a grid pattern based on text width and page dimensions
5. Sets the opacity using PDF's native transparency support
6. Saves the watermarked PDF as a downloadable file

Text watermarks add negligible file size. Image watermarks embed the image once and reference it on each page, so file size increase is minimal even for multi-page documents.

Tips for Effective Watermarks

1. Keep opacity between 20-40% for background watermarks that don't obstruct content.
2. Use diagonal rotation (-45°) for the classic "stamp" look that's visible but not intrusive.
3. Choose tiled position for maximum protection — it's much harder to edit out a tiled watermark than a single centered one.
4. Use red for warnings (DRAFT, CONFIDENTIAL) and gray for branding (logos, company names).
5. Font size 60pt works well for most A4/Letter documents. Go larger (80-120pt) for single-word stamps, smaller (30-40pt) for longer text.

PDFJolt makes watermarking PDFs simple, fast, and private. Customize every aspect of your watermark, preview it in real time, and apply it to your entire document in seconds — all without your files ever leaving your browser.