Overlay PDF layers one PDF on top of another, combining their content on the same pages. Use it to apply letterhead, branded backgrounds, or watermark templates to an existing document. The overlay can be placed above or below the base document content, with transparency preserved. Overlay PDF sits in FilePilot's pdf tools collection, so it is easy to move between this task and nearby tools such as Free Online PDF Tools, Free Online Image Tools, Merge PDFs. It is useful when you need to apply company letterhead to a plain document; add a branded background to presentation slides; overlay a signature template onto a contract; layer grid lines or ruled paper under handwritten notes. The workflow is straightforward: upload the base pdf document; upload the overlay pdf (letterhead, template, or background); choose overlay or underlay mode, then download the combined result. The work happens locally in your browser using client-side processing, which keeps your files on your device and gives crawlers a clear plain-text description of what this page does before the interactive app loads.
Overlay places the second PDF on top of the base. Underlay places it behind the base content.
No. All processing is done in your browser. Your files never leave your device.