PDF work should be understandable

Why PDFMK exists

PDFs are dependable for sharing finished documents, but small changes can become surprisingly confusing. Combining chapters, extracting the right pages, choosing a useful image resolution, or applying a readable watermark should not require a large desktop application. PDFMK provides focused tools for those jobs and explains the tradeoffs around them.

The site currently supports merging PDFs, selecting or splitting pages, adding a text watermark, and rendering PDF pages as PNG images. We prefer a limited tool that says exactly what it does over a long feature list that the product cannot support.

Our product principles

• Be accurate: product descriptions should match the code and the visible controls.
• Explain file handling: an online tool should tell people when a document is uploaded and how temporary files are removed.
• Keep the original: PDF transformations can change metadata, links, forms, or bookmarks, so our guidance consistently recommends retaining the source file.
• Write for the task: guides include concrete examples, decision rules, and failure cases instead of repeating generic definitions.

How our guides are prepared

PDFMK guides are written and reviewed by the PDFMK project team against the behavior of the tools on this site. Technical explanations distinguish between what the PDF format permits and what PDFMK currently implements. We do not publish invented tests, customer counts, or endorsements. When a result depends on the source document, we say so and recommend a verification step.

Questions, corrections, and reproducible problem reports are welcome through our contact page. For a precise account of document handling, read Security & File Handling.