PDF Bookmarks — Edit the Outline
The panel down the left of a PDF reader is the outline, and almost nothing that generates a PDF bothers to write one. Drop a file in and its existing bookmarks appear as editable text; change them, add the ones a 200-page scan should have had, and write the file back. Nothing is re-rendered — only the outline is replaced.
Drop a PDF here or click to select
One file · its existing outline loads below
Nothing to hand? sample-10-pages.pdf has no outline — a good file to add one to. More free sample files.
The format
One bookmark per line: the title, then ::, then the page it jumps to.
Indent with two spaces (or a tab) for each level of nesting.
Cover :: 1
Executive summary :: 2
Findings :: 5
Method :: 5
Results :: 8
Table 3 :: 11
Appendix A :: 24
A tab or two or more spaces between the title and the number works as well as ::,
so a list pasted out of a spreadsheet usually needs no editing. If a line has no separator at all,
a trailing number is read as the page and the rest is the title.
What gets written
Each entry becomes an outline item pointing at its page with an XYZ destination and no
zoom change — jump to the page, leave the reader's zoom alone, which is what every other tool
writes and what people expect. Nested entries start collapsed. The document's page mode is set so
the sidebar opens by itself the first time the file is viewed.
Nothing else in the file is touched: the pages, their content streams, the form fields and the metadata are written back exactly as they came in. This is not a re-render, so it cannot change how a page looks.
Where bookmarks come from — and go
- Scanners write none. A 300-page scanned binder is one flat stack; the outline is the difference between usable and not.
- Merging destroys them. Most merge tools — this site's included until now — drop every outline on the floor. Merge PDFs now writes a bookmark per file and nests each file's own outline underneath it, renumbered.
- Word and LaTeX write good ones from headings, then a "print to PDF" step throws them away. If your outline vanished, that is usually where.
- Splitting keeps the pages, not the outline. After splitting, each part needs its own — which is a two-minute job here.
Reading an outline back
Drop a file that already has bookmarks and they come back in exactly the format above, indentation and all, so this doubles as a way to extract an outline: copy the text out, edit it, keep it alongside the document, or paste it into the tool again after re-generating the PDF. Page numbers come from resolving each bookmark's destination, so they are the pages a reader actually jumps to — not the ones printed on the paper.
FAQ
My bookmarks point at the wrong pages after editing.
The numbers here are physical page positions, counting from 1, not the numbers printed on the page. A report whose body starts at printed page 1 on the fifth sheet needs 5, not 1. Open the file in the viewer to check the position of a page.
Can a bookmark point somewhere other than the top of a page?
Not from here. The destination written is "this page, current zoom", which is robust — a bookmark with a fixed scroll position and zoom behaves oddly on a phone and on a different page size. Precise destinations are a job for a full PDF editor.
Does removing bookmarks remove the links inside the document?
No. Link annotations on the pages themselves — a clickable table of contents, cross-references, external URLs — are separate objects and are untouched. Extract links lists those.
Is the file uploaded?
No. It is parsed and rewritten in your browser, and the result is a download from the page itself.
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- Repair a Corrupted PDF — Rebuild a file that will not open.
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- Compress PDF to a Target Size — Hit a target like 100 KB or 500 KB.