Merge two or more PDF files into one, in the order given. Runs entirely on this machine — the file is read and written locally and never sent anywhere.

Split a PDF by 1-based page ranges (one output file per comma group, e.g. "1-3,5"), or extract specific pages into a single PDF (e.g. "1,3,5"). Provide exactly one of ranges or pages. Runs entirely on this machine — the file is read and written locally and never sent anywhere.

Rotate pages by a multiple of 90 degrees. Omit pages to rotate every page. Runs entirely on this machine — the file is read and written locally and never sent anywhere.

Stamp a text watermark on every page. Runs entirely on this machine — the file is read and written locally and never sent anywhere.

Stamp sequential Bates numbers ({prefix}{zero-padded n}) on every page. Runs entirely on this machine — the file is read and written locally and never sent anywhere.

Strip document metadata: clears title, author, subject, keywords, creator and the CreationDate/ModDate in the info dictionary, AND deletes the document-level XMP metadata stream (the copy Acrobat/Word/InDesign write). Note: pdf-lib rewrites /Producer with its own signature on save, so that one field is replaced rather than emptied. Runs entirely on this machine — the file is read and written locally and never sent anywhere.

Return the number of pages in a PDF. Runs entirely on this machine — the file is read and written locally and never sent anywhere.