Short answer: use a merger that copies pages with their link annotations instead of re-drawing them. Adobe Acrobat's Combine Files keeps web links and internal links and can keep bookmarks; the free command-line tool qpdf (qpdf --empty --pages a.pdf b.pdf -- merged.pdf) keeps the links on every page but drops bookmarks unless you start from the first file. Links that pointed from one file to another file keep pointing to that file and must be fixed by hand. Always test a few links in each part after merging.
qpdf behaviour per the qpdf manual (read 9 November 2026); PyMuPDF / HelpRange merge tool tested on 9 November 2026. Updated 9 November 2026. Disclosure: HelpRange is our product.
Combine up to 25 PDFs into one file. They are merged in the order you select them. No sign-up – files are deleted within 30 minutes.
Send a link instead of an attachment: only specific people can open it, downloads and forwarding are blocked, every page is watermarked, and you see who read what – page by page.
A PDF "link" is an annotation sitting on top of a page. What happens to it depends on its target:
| Method | Keeps web and page links? | Keeps bookmarks? | Free? |
|---|---|---|---|
| Adobe Acrobat Pro/Standard: Combine Files | Yes (links between separate files need editing) | Yes, can keep each file's bookmarks; check Options | No (paid subscription) |
| Acrobat: drag a file into the Page Thumbnails panel of another | Yes | Keeps the open file's bookmarks; reported as a reliable workaround | No |
qpdf --empty --pages a.pdf b.pdf -- | Yes | No (outline comes only from a primary file) | Yes, open source |
qpdf a.pdf --pages . b.pdf -- | Yes | First file's bookmarks only | Yes |
pdftk a.pdf b.pdf cat output merged.pdf | Web links reported kept | Usually lost; can be re-added with dump_data / update_info | Yes |
PyMuPDF (insert_pdf), e.g. the HelpRange merge tool | Yes (tested 9 November 2026) | No (can be rebuilt with set_toc in code) | Yes |
| macOS Preview (drag pages into the sidebar) | Varies by macOS version: test | Often lost | Yes |
| Online mergers in general | Most keep web links; some flatten pages and lose all links | Often lost | Usually, with limits |
Methods marked "reported" or "varies" are based on user reports rather than documentation; test with your own files.
Install qpdf (for example brew install qpdf on a Mac or the Windows installer from the qpdf project), then:
qpdf --empty --pages a.pdf b.pdf c.pdf -- merged.pdfqpdf a.pdf --pages . b.pdf c.pdf -- merged.pdfqpdf --empty --pages a.pdf 1-5 b.pdf -- merged.pdfThe qpdf manual explains that form fields, outlines and article threads are copied "in their entirety from the primary input file", while page labels are kept from all files. If you need the bookmarks of every part, build a combined outline afterwards in Acrobat or with a script (PyMuPDF's get_toc on each file plus set_toc on the result, offsetting page numbers).
Merging should not reduce quality either: copying pages does not recompress images. If your file got blurry, the tool rasterised it. See how to merge PDFs without quality loss.
A merged pack (a proposal with appendices, a due diligence bundle, a course workbook) often goes to people outside your company. Instead of attaching it, you can upload it to HelpRange and share a link: you see who opened it and which pages they read, and you can turn off downloading. The free merge tool deletes files within 30 minutes.
Usually for one of three reasons: the tool rebuilt or flattened the pages and dropped link annotations; the link pointed to a named destination stored at document level, which the merge did not copy; or it was a link to another file (for example "see chapter2.pdf") that still points to that separate file after merging.
Yes, Acrobat's Combine Files keeps web links and links within each file, and can keep each file's bookmarks. Links between the original separate files still point to those files and need to be edited to point to pages in the combined PDF. Combine Files needs Acrobat Pro or Standard.
Use qpdf: qpdf --empty --pages a.pdf b.pdf -- merged.pdf keeps the links on each page. Bookmarks are taken only from a primary input file, so with --empty none are kept; start from the first file instead (qpdf a.pdf --pages . b.pdf -- merged.pdf) to keep its bookmarks.
Yes. In our test on 9 November 2026 the free merge tool kept web links and internal page links (re-pointed to the right page in the merged file). Bookmarks from the separate files were not kept.
Open the merged file, click one web link, one table-of-contents link in each part and one bookmark per part, and confirm each lands on the right page. In Acrobat, the Link tool highlights every link box so you can spot missing ones.
Send a link instead of an attachment: only specific people can open it, downloads and forwarding are blocked, every page is watermarked, and you see who read what – page by page.