Links and bookmarks in PDFs: what it is and what it is for

1What are links and bookmarks in a PDF?

Links, or hyperlinks, are areas of the page that react to a click. They can open a web page, compose an email, jump to another page in the same document or open a related file. Bookmarks, on the other hand, form a sidebar outline that shows the structure of the document, with chapters and subchapters you can expand and tap to go straight to each part.

They are navigation tools. In a 200-page manual, a good set of bookmarks turns searching into a two-second action, and an index with internal links lets you jump from one chapter to another without scrolling.

2How do they work under the hood?

A link is an annotation: an invisible rectangle over the page with an associated action, like opening an address or going to a destination. An internal destination is a specific point on a page, sometimes with a name, that other links or bookmarks can use. That is why an internal link depends on the numbering and structure of the document.

Bookmarks are a tree: each entry has a title, a destination and, optionally, child entries. They are stored separately from the page content. That explains why tasks like extracting, reordering or deleting pages can leave bookmarks pointing to wrong or nonexistent places.

3Common problems and how to avoid them

The most common is a link that stops working after merging or splitting files. An internal link that pointed to page 12 can end up pointing to the wrong content if pages moved, or if the destination no longer exists in the new file. External links usually survive better, but not always.

Another is that, when converting a Word document to PDF, text that looks like a link isn't really a hyperlink, or the address points to a site that has changed. It also happens that manual tables of contents, typed with dot leaders and numbers, look like an index but lead nowhere.

• After merging or splitting: test the internal links.
• After reordering pages: check the bookmarks.
• External addresses: confirm they are still valid.
• Manual indexes: turn them into real links from the original.

4When they are lost and when to remove them

Links and bookmarks are lost when the PDF is rebuilt without those elements: when converting pages to images, when printing to PDF from another program or when flattening certain content. A page converted to an image is just pixels: there are no clickable areas or text to link.

Sometimes removing them is what you want. If you are sending a document with sensitive data, a link can reveal internal addresses, and a bookmark can show titles that shouldn't be seen. When redacting, also check that bookmarks don't repeat the text you just covered.

If you publish a long document for other people, spend a few minutes going through it the way a reader would: open the bookmarks panel, click three or four entries at random and try a couple of external links. It's a short review that spares you the frustration of an index that leads nowhere.

5Practical tips to keep them

The best approach is to create links and bookmarks in the original document and export at the end, using the option to create bookmarks from headings that word processors offer. Then do your PDF operations before the final sign-off, and test the important links in the final file.

If you need a merged document, merge first and review afterward; if you need to separate a part, check that internal links leaving that part don't point to pages that stayed in the other file. And always keep the original with all its elements.

6Links, bookmarks and Rayo PDF GO

Rayo PDF GO helps you organize documents with Merge PDF, Split PDF, Organize PDF and Delete PDF pages, all on your device. After any of these operations, open the result and test your links and bookmarks, because they may have moved or not survived.

With Redact PDF each affected page is converted into an image, so its links stop being interactive. Flatten PDF also turns what was interactive into fixed content. To add new elements to the document, Edit PDF and Page numbers work as a complement.