Add Bookmarks to PDF Online Free — Table of Contents

Q: My PDF already has bookmarks — what happens?

They are loaded into the editor automatically, so you can extend, reorganize, or delete them before downloading — nothing is lost unless you remove a row yourself.

Drop your PDF here

Select PDF

one file at a time · .pdf only

Done!

Everything happened inside your browser — your file was never uploaded anywhere, so there is nothing to delete.

Give Your PDF a Clickable Table of Contents

Open a 200-page PDF with no bookmarks and you're scrolling blind. No chapters, no sections, no way to jump — just an endless ribbon of pages. When you add bookmarks to PDF files, you build the navigation the document should have had: a clickable table of contents in the reader's sidebar, with chapters that expand into sub-sections.

Bookmarks (technically called the document outline) are the single biggest usability upgrade you can give a long PDF. Readers open the sidebar, click "Chapter 4 — Methodology", and land exactly there. On phones, where scrolling through 200 pages is torture, bookmarks turn an unreadable file into a navigable one.

EzySize's bookmark editor runs in your browser — free, no account, nothing uploaded. You create entries, point each at its page, nest them into chapters and sub-sections, and download a PDF whose navigation works in every major reader: Adobe, Chrome, Preview, and mobile apps alike.

Add bookmarks to PDF: build a clickable table of contents

Drop your PDF onto the upload area. The file opens locally in your browser. Long reports, ebooks, manuals, theses — anything readers need to navigate.
Scan the document's structure. Flip through and note the real hierarchy: parts, chapters, sections, appendices. A good bookmark tree mirrors the document's actual headings — don't invent structure that isn't there.
Add top-level bookmarks for each chapter. Create an entry per chapter and point it at the page where the chapter starts. Keep titles short and match the document's own heading text so readers recognize them.
Nest sub-sections underneath. Drag or indent entries to build the hierarchy: Chapter 4 contains 4.1, 4.2, 4.3. Two to three levels is the sweet spot — deeper nesting gets fiddly in sidebar panels.
Test the navigation, then download. Click through a few bookmarks to confirm they land on the right pages (off-by-one errors are the classic mistake). Download the bookmarked PDF — the outline travels with the file everywhere it goes.

Real-world use cases

Ebooks that feel professional. Readers expect to jump between chapters. An ebook without bookmarks feels amateur; with a full outline, it behaves like a real publication on Kindle apps and tablets.

Company handbooks people actually use. Nobody reads a 90-page handbook cover to cover. Bookmarks let employees jump straight to "Leave Policy" or "IT Security" — which is the difference between a handbook that's used and one that's ignored.

Theses and dissertations. Examiners navigate by chapters and appendices. A bookmarked thesis makes their job easier, and examiners who can find things are happier examiners.

Technical manuals in the field. A technician on a factory floor needs "Troubleshooting — Error 47" in two taps, not after scrolling 300 pages on a phone. Bookmarks are a usability feature with real operational value.

Merged reports that need structure. After combining several PDFs into one, the result is a flat stack of pages. Adding a bookmark per source document restores the structure — use Merge PDF first, then bookmark the result.

Pro tips for outlines that work

Mirror the document's headings exactly. If the chapter is titled "Results and Discussion", the bookmark should say "Results and Discussion" — not "Results". Mismatched labels confuse readers who are scanning for a known heading.
Point at the chapter's first content page. Not the divider page, not the blank page before it — the page where the actual text begins. Readers click a bookmark and expect content, not whitespace.
Don't bookmark every heading. A 200-bookmark outline is as useless as none. Bookmark chapters and major sections; leave minor sub-headings to the reader's scrolling. Aim for 10–40 entries for most documents.
Add front and back matter. "Cover", "Table of Contents", "Appendix A", "Index" — readers look for these too. A complete outline covers the whole document, not just the middle chapters.
Combine with good metadata. After bookmarking, set the document's title and author with Edit PDF Metadata so the file is properly labeled as well as properly navigable. And if you ever need to break the document apart again, Split PDF by Bookmarks can divide it along the outline you built.

PDF bookmarks and outlines, explained

Bookmarks vs. a printed table of contents

A printed TOC is a list of page numbers you still have to scroll to. Bookmarks are clickable — one tap jumps you there. The best documents have both: the printed TOC for overview, the bookmark outline for navigation. A PDF bookmark maker creates the clickable kind.

What "add outline to PDF" means

"Outline" is the technical name for the bookmark tree in the PDF specification. So add outline to PDF and "add bookmarks to PDF" describe the same operation — building the hierarchical navigation structure that readers see in their sidebar. You can add outline to PDF online in minutes with the bookmark editor: create the entries, nest them, and download.

Do bookmarks work on phones?

Yes — every major mobile PDF reader (Adobe Acrobat mobile, Apple Books, Chrome on Android) shows the bookmark sidebar. On small screens bookmarks matter even more, because scrolling long documents on a phone is painful. A PDF bookmarks maker that nests chapters properly gives mobile readers the navigation they need most.

Long documents deserve navigation. Spend twenty minutes on the outline and your readers will never scroll blind again.

How it works

Add your PDF
Drop one PDF into the box. It is read locally — nothing is uploaded.
Build your bookmark list
Tap “+ Add bookmark”, type a chapter title, choose the page it should jump to, and set its nesting level.
Download
Hit Add Bookmarks to PDF. Your file downloads with a real, clickable outline in any PDF reader.

Tips

Nest like a book. Chapters at level 1, sections at level 2, sub-sections at level 3 — readers can expand and collapse them.
Keep titles short. Bookmark panels are narrow; “Chapter 3 — Results” beats a full sentence.
Front matter counts. Page numbers in the list are the PDF’s own pages (page 1 = the first page of the file), not the printed numbers.
Bookmarks are free. Adding an outline barely changes the file size — it only stores titles and page links.

Frequently asked questions

How do I add bookmarks to a PDF?

Add your PDF, tap “+ Add bookmark” for each chapter, type its title, pick the page it should jump to and set its nesting level. Then hit Add Bookmarks to PDF and download the file — the outline works in Adobe Reader, Chrome, and every major PDF app.

Can bookmarks have sub-sections?

Yes. Set a bookmark to level 2 and it nests under the level 1 bookmark above it; level 3 nests under level 2. This is exactly how published books structure their tables of contents.

Will bookmarks work on phones?

Yes. The outline is written into the PDF itself using the standard PDF outline format, so it shows up in mobile readers like Adobe Acrobat Reader and Apple’s Files/Books apps.

Is my PDF uploaded anywhere?

No. The whole process runs in your browser — your document never leaves your device, which also means the tool works offline once the page has loaded.

My PDF already has bookmarks — what happens?

They are replaced by your new list. If you want to keep the old ones, note their titles and pages first and re-add them in the editor.

How do I add bookmarks to a PDF online for free?

Drop the PDF into the bookmark tool, create an entry for each chapter pointed at its starting page, nest sub-sections underneath for hierarchy, test a few jumps, and download. The outline works in Adobe, Chrome, Preview, and mobile readers — and the file never leaves your browser.

What is the best free PDF bookmark editor?

Look for nested hierarchy support (chapters containing sub-sections), per-entry page targeting so each bookmark lands exactly where it should, a preview to test jumps before downloading, and local browser processing so confidential documents stay private. This tool provides all four with no account and no cost..

How do I create PDF table of contents that's clickable?

Build a bookmark outline: one top-level entry per chapter, nested entries for sections, each pointing at the right page. Unlike a printed page-number list, these bookmarks are clickable in the reader's sidebar — one tap jumps straight to the chapter.

Can I add an outline to a PDF that already has some bookmarks?

Yes. The tool reads the existing outline and lets you extend, reorganize, or rebuild it as needed. If the current bookmarks are a mess — wrong pages, cryptic labels — it's often faster to clear them entirely and build a clean, properly nested hierarchy from scratch.

Is there a free PDF bookmark maker that works on mobile?

Yes — this one runs in any modern mobile browser. And the bookmarks you create work on phones too: every major mobile PDF reader shows the outline sidebar, where navigation matters most because scrolling long documents on a small screen is painful.