PDF BASICS / START HERE
What is a PDF, and which tool should you use?
PDF is a page-layout format designed to keep text, images and page geometry consistent across devices. This guide explains what a PDF contains, why files behave differently, and how to choose a practical next step.
A PDF is a fixed-layout document. It is excellent for sharing and printing, but changes such as stamps, page numbers, watermarks or image conversion should be previewed before the final file is distributed.
PDF is a document container
A PDF can contain text, vector shapes, raster images, fonts, annotations, forms and metadata. A scanned PDF may contain only page images, which affects search and editing.
Layout is part of the file
Page size, orientation, margins and rotation are stored with each page. Tools that add marks or convert pages should respect those properties instead of assuming every page is the same.
Output needs a review pass
After any transformation, check page count, orientation, readable text, mark placement, file name and whether the result opens in your normal PDF reader.
Choose a PDF task
Need a visible mark?Stamp PDFadds stamps, seal images and seam seals.
Need navigation?Add page numbersadds page numbers with position and format controls.
Starting with images?Images to PDForders JPG, PNG or WebP pages into a PDF.
Need distribution context?Watermark PDFadds text or image watermarks.
What PDF SealBox does not promise
PDF SealBox creates visible document outputs. It does not provide OCR, legal advice, notarization, certificate-backed digital signatures, identity verification or a guarantee that a particular document meets a regulated filing rule.