BASALT · JOURNAL
How to split a PDF by bookmarks on Mac
Large manuals, productions, and reports often use bookmarks to define logical sections. Splitting by those boundaries creates smaller files without making someone guess where a chapter or exhibit begins.
Review the bookmark hierarchy
Check that top-level bookmarks represent the files you want and that nested entries do not create accidental fragments. Verify destinations and page labels before splitting. Rename ambiguous headings into filenames that make sense outside the original document.
Preserve or remove supporting content deliberately
Decide whether each output needs a cover page, headers, footers, attachments, comments, or metadata. A split file can still expose sensitive data carried in an attachment or hidden layer, even when its visible pages are correct.
Verify every output
Open each file, check page range and order, test bookmarks, and search for values that should not be present. Confirm that no output is empty or missing a final page. Keep the unsplit source as the controlled master.
Frequently asked questions
What if the PDF has no bookmarks?
Create boundaries from a table of contents, page labels, or a written page-range plan, then verify the result.
Do bookmarks survive splitting?
They can, but their destinations may need adjustment. Test representative links in every output.
Should each split file keep the original metadata?
Only when it is appropriate. Update titles and remove personal metadata that no longer applies.
Doing it in Basalt
Basalt splits PDFs on-device and helps you review page ranges, document properties, and hidden content before distributing the individual files. Download Basalt.
Redaction that proves itself
Basalt destroys the content you mark, then re-opens the file it wrote and proves the content is gone before it saves anything. Your documents never leave your Mac.