Recompress JPEG images in a PDF and compare file size

Before you start

Define the document’s purpose

Keep the original and decide whether you need changed pages, a new document, extracted information or a report. A readable page is only part of a PDF: forms, bookmarks, annotations and existing signatures may also matter. Check this guide’s supported features before choosing the result for a formal submission.

For a tool that selects pages, distinguish positions in the file from numbers printed on the pages. For a document created from entered values, review the source values and their order instead. If size, placement or print layout can be set, test a page with dense text or content close to an edge before applying the choice more widely.

Make a short plan of the source files, their order and the changes you intend. For an existing PDF, note any page selection and the functions that must survive; for a newly generated document, keep the values from which it is built. If a problem appears only after a later operation, compare the intermediate copy with the original to locate the first change. Record the settings needed by the recipient, so a visually acceptable trial is not mistaken for a document that meets every requirement.

Check content and document behavior

Open the saved file and inspect the beginning, end and any place where content was moved, combined or divided. Compare counts and values with the source or your input list. When the output is a report or extracted text, check a few findings on the actual pages rather than treating an empty report as proof that nothing relevant exists.

If printing is the purpose, use print preview and a test sheet to check reading size and placement. Where interactive fields, links or signature verification matter, test them separately; appearance does not establish that they still work. If processing fails, review protection, format and the stated limits without discarding the original.