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Overlay PDF Online

Use this free Overlay PDF Online online tool to overlay one PDF on another with live preview, opacity, position, and page alignment. It is built for students, teams, and professionals who need a clean result quickly. Upload, process, and download in a few clicks. Up to 50 MB per file.

Built & maintained by the OptaPDF Team Editorial standards Free · No sign-up · Files auto-deleted in 30 min
Secure TLS/SSL encryption 100% free, no signup Fast browser-based processing
1

Upload & Configure

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Drag & drop your Base PDF here

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Drag & drop your Overlay PDF here

70%

Behind mode shows through where your document background is transparent.

2

Preview & Download

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Upload a base PDF to see a live preview

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🔒 100% private — your files are processed in your browser and never uploaded.

Trustpilot

How to Use Overlay PDF Online

Complete your task in four clear steps.

1

Step 1

Load your base PDF (the document) and your overlay PDF (a letterhead, stamp, signature, or watermark) - both stay in your browser and are never uploaded.

2

Step 2

Use the live preview to see the overlay composited onto each base page in real time as you change settings.

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Step 3

Dial in the overlay opacity (a faint watermark or a solid stamp), the position (center or any corner), and the page alignment (match pages one-to-one, repeat the first overlay on every page, or stamp only the first page).

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Step 4

Click Process Overlay, then Download - the layered PDF is generated locally on your device.

Why Choose OptaPDF for Overlay PDF Online?

  • ✅ Processes in your browser using pdf.js and pdf-lib, so the base and overlay PDFs are not uploaded.
  • ✅ Live preview shows the overlay position, opacity, page alignment, and layer before export.
  • ✅ Use foreground mode for stamps and signatures, or background mode for letterhead and stationery.
  • ✅ Preserves crisp PDF layers instead of turning the page into a low-quality screenshot.

Privacy Guarantee

PDF Overlay runs directly in your browser using client-side PDF libraries. Your base PDF and overlay PDF are not uploaded to the OptaPDF server, and the finished file is generated on your device. OptaPDF works on iOS, Android, Chrome, Safari, Edge, and desktop browsers without an app installation.

Common Uses for Overlay PDF Online

  • Apply company letterhead behind a plain invoice, quote, report, or certificate.
  • Stamp a PDF with APPROVED, PAID, DRAFT, CONFIDENTIAL, or RECEIVED.
  • Place a signature block or seal PDF on top of a contract.
  • Overlay a template, border, or form background under exported text.
  • Create a transparent watermark PDF once and reuse it across multiple documents.

Best Results Checklist

  • Use Behind content for letterhead so text remains easy to read.
  • Use Over content for stamps, signatures, seals, and approval marks.
  • Set opacity between 20% and 40% for watermarks, and 80% to 100% for stamps.
  • Choose Overlay First Page on All when a one-page letterhead should repeat across a multi-page document.

Troubleshooting Overlay PDF Online

Quick fixes for common file and output issues.

Switch the Layer control to Behind content or lower the opacity.
Use Single Overlay on First Page Only in the page alignment control.
Lower the opacity before processing and check the live preview.
Unlock protected PDFs first, because browser libraries cannot read encrypted documents without access.

⭐ Related Productivity Tools

Keep going — these tools pair perfectly with what you just did.

Watermark Pdf → Edit Pdf → Sign Pdf → Merge Pdf →
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How to Overlay One PDF on Another Online for Free →

Frequently Asked Questions About Overlay PDF Online

Get answers to common queries regarding security, speeds, and bounds of this tool.

Upload your base (background) PDF and your second (foreground) PDF, set the position and opacity, then click process. OptaPDF draws the second document over the first page by page and returns a single combined file.
Merging places pages one after another, so a 2-page and a 2-page file become a 4-page document. Overlaying stacks them, so both documents appear together on the same page - which is what you want for letterheads, stamps, or watermarks.
Yes. You can set the opacity from 10% to 100% and choose where the overlay sits - stretched full page, centred, or in any corner - plus scale it down and place it behind the base content if needed.
A PDF Overlay is a process that merges two PDF files by drawing the pages of the second document directly on top of the pages of the first document. It acts like printing a text on a pre-existing background sheet.
Simply upload both documents on our PDF Overlay tool, click process, and download the merged output instantly.
Yes! Because the engine merges vectors natively, text blocks from both documents remain fully searchable and copyable.
The file will combine both original filenames, e.g., background_foreground_overlay.pdf.
Yes. Files are processed in-memory over HTTPS and auto-deleted within 30 minutes.
Yes, our engine automatically scales the overlay bounds to align beautifully with the background page dimensions.
No, OptaPDF is completely free and adds zero watermarks.
Yes, our responsive web interface is optimized for mobile file managers and browsers.
We support uploads up to 50MB.
You must first decrypt files using our Unlock PDF tool before merging.
Yes. Use the Layer control to choose Over content or Behind content. Over content (the default) puts the overlay on top of the page - ideal for stamps, signatures, and marks like APPROVED or CONFIDENTIAL that must be clearly visible. Behind content places the overlay beneath your document text, which is what you want for letterheads and branded stationery so the text reads cleanly over the top. Lower the opacity in either mode for a faded watermark effect.
The most common uses are adding a company letterhead to every page, stamping a document with APPROVED, PAID, DRAFT or CONFIDENTIAL, dropping a signature block onto a contract, applying a semi-transparent watermark, or laying a branded template over a plain export. Any file saved as a PDF can act as the overlay layer.
You choose. Match Pages overlays page 1 on page 1, page 2 on page 2, and so on. Overlay First Page on All repeats a single overlay - such as a letterhead - on every page of the base document. Single Overlay stamps only the first page. If the overlay has fewer pages than the base, the last overlay page is reused.
No. The overlay is drawn as a true vector layer over the base page, so both documents keep their original text, fonts, and graphics. The result stays sharp at any zoom level and the text remains selectable and searchable.
Overlay places an entire PDF page on top of another, so it is the right choice for a full letterhead, a signed page, or a designed template. The Watermark PDF tool is purpose-built for repeating text or a logo at a set angle and opacity, with an over-text or under-text layer option. Use overlay for whole-page layers and watermark for simple repeating marks.