Guide · 2 min read
PDF Format Explained
Learn what a PDF is, how PDF files store content, and which tools suit each task.
Maintained by Leslie · Updated
Examples describe expected workflows unless a dated test is explicitly identified. Check the downloaded result against your own document before sharing it.
What a PDF is
PDF, or Portable Document Format, was designed to keep a document looking the same on every device. It stores text, vector shapes, fonts, and images inside one self-contained file.
A PDF can include a text layer, which makes text searchable and extractable, or contain only images when the file comes from a scanner.
Text layers versus scanned pages
Documents created by word processors and design tools usually include a text layer. Scanned PDFs store pictures of pages, so they need OCR before the text can be searched or edited.
Use PDF to Word when a text layer exists. Use OCR PDF first for scanned documents.
Choosing the right tool
Merge and Split PDF manage page collections. Compress PDF reduces file size. Protect PDF controls access, and Watermark PDF adds ownership text.
The PDF workflows process selected files in the browser. Keep an original copy and check the output before using it as your working document.
Diagnose one page before choosing a workflow
Open a representative page, select a sentence, paste it into a text editor, and zoom into small lettering. A successful copy suggests extractable text; a sharp zoom alone does not, because both vector artwork and high-resolution scans can look clear.
A single PDF may mix selectable report pages and scanned attachments. Check one page of each kind. Use page tools when the task is to reorder or remove pages, PDF to Word for reusable text, and OCR for scans that need recognition. None of those choices makes the file an editable copy of its original design.
Keep an original and define the required result
Consider a searchable report with a scanned receipt appendix. Merging can put them in one packet; it does not give the receipts text recognition. Compressing the merged packet here turns every page into an image, including the report pages that previously had selectable text.
Before processing, decide whether you need appearance, searchable text, interactive fields, or exact source formatting. Afterward, check those specific requirements in the downloaded file. A PDF extension and a successful open do not prove accessibility, archival conformance, intact signatures, or complete conversion.