Learn
The PDF page-count and text-extraction behavior described here follows the ISO 32000 PDF specification that Mozilla’s PDF.js implements. Mozilla PDF.js.
Learn
How PDF Page and Word Counts Work
Why viewers disagree, how text-layer word counts are computed, and what to do with a scanned PDF.
Page count is metadata
The page count of a PDF is stored in the file itself. The PDF page counter reads that value directly. Adobe, Preview, and every third-party viewer read the same value, so they agree on the page count for a well-formed PDF. Where they disagree, one viewer usually treats trailing blank pages or an inserted cover as a separate page while the other does not.
Word count is a text extraction
PDFs do not store word count. Every tool computes it by iterating the pages, pulling the text content, and tokenizing on whitespace. The number moves depending on how well the extraction handles: multi-column layouts (word order may swap between columns), hyphenated line breaks (naive tokenizers double-count), soft hyphens (should be stripped), footnotes and headers (Word’s counter can exclude them; a paste-then-count workflow cannot).
Scanned PDFs
A scanned PDF is an image of pages. There is no text layer to extract. Every word counter will report zero for a scanned document. Fix by running OCR: Adobe Acrobat’s Enhance Scan tool, macOS Preview’s built-in text recognition, or Adobe’s free online OCR. Once the file has a text layer, the counter reads it normally.
Password-protected PDFs
Encrypted PDFs cannot be counted until you unlock them. There is no way around this without the password; PDF.js, Acrobat, and every other viewer respect the file’s encryption.
Try the counter
Drop your PDF on the PDF page counter. Page count is instant. Word count runs for text-layer PDFs.