UtilityKit

500+ fast, free tools. Most run in your browser only; Image & PDF tools upload files to the backend when you run them.

PDF Bookmarks Editor

View, add, rename, indent, and reorder PDF outline (bookmarks) — browser-only

About PDF Bookmarks Editor

PDF Bookmarks Editor lets you read, edit, restructure, and rebuild the outline (table-of-contents pane) of a PDF without installing Acrobat. The tool reads the existing outline tree using pdf.js, flattens it into an editable list with indentation levels, and lets you rename entries, change the destination page, indent and outdent to nest entries, reorder rows up and down, add new bookmarks, and delete unwanted ones. When you click Save PDF, the editor uses pdf-lib to write a fresh hierarchical outline dictionary and updates the document's PageMode so PDF readers open the file with the bookmarks pane visible. Every change is local to your browser — your document is never uploaded. This is the right tool for adding a TOC to a multi-chapter ebook, cleaning up auto-generated outlines from Word exports, or producing a navigable reference document from a long technical manual.

Why use PDF Bookmarks Editor

Read the Existing Outline

Every bookmark already in the PDF appears immediately, with the right indentation level for its nesting.

Inline Editing

Rename titles, change page numbers, indent, outdent, reorder, add, or delete — all without leaving the page.

Preserves Hierarchy

Save rebuilds a proper hierarchical outline dictionary, not a flat list — readers show expand/collapse arrows correctly.

Auto-Open with Bookmarks Visible

The output PDF is set to open with the outline pane shown, so readers see your TOC immediately.

Browser-Only Processing

pdf.js reads the outline, pdf-lib writes the new one — UtilityKit never sees any document data.

Add a TOC from Scratch

Even if the source PDF has no outline at all, you can build a fresh TOC entry-by-entry.

How to use PDF Bookmarks Editor

  1. Upload the PDF whose outline you want to edit — up to 50 MB, processed entirely in your browser.
  2. The existing outline is parsed and shown as a flat list with indentation showing nesting depth.
  3. Edit any title in place by typing in the title field; change destination page via the page-number input.
  4. Click '»' to indent a row under the previous bookmark, or '«' to outdent it back up.
  5. Use the up/down arrows to move a bookmark earlier or later in the list.
  6. Click '+ Add bookmark' to append a new entry; click '✕' on any row to delete it.
  7. When done, click Save PDF to download a new file with the rebuilt outline.

When to use PDF Bookmarks Editor

  • When publishing a multi-chapter ebook or report and the auto-generated outline is missing, broken, or wrong.
  • When cleaning up Word/Pages PDF exports where every heading turned into a bookmark and you want only the H1/H2 levels.
  • When merging several PDFs and the combined outline has duplicate or misaligned page numbers that need fixing.
  • When localising a document and you need to translate every bookmark title without touching the body content.
  • When a long reference manual has no TOC and you want to add one for navigation in PDF readers.
  • When restructuring a research paper, thesis, or whitepaper where chapters were reordered after the outline was built.

Examples

Cleaning up a Word export

Input: report.pdf — 47 bookmarks (every H1, H2, H3), keep only H1 and H2

Output: report-bookmarks.pdf — outline trimmed to 18 entries with two indentation levels, much easier to navigate

Adding a TOC to a manual

Input: manual.pdf — no outline at all, add 12 chapter entries pointing to pages 1, 14, 28, 41, 56, 71, 88, 104, 119, 137, 152, 168

Output: manual-bookmarks.pdf — new outline pane opens automatically in any PDF reader

Translating bookmarks

Input: guide.pdf — 22 English bookmarks, rename each to French translation, leave page numbers alone

Output: guide-bookmarks.pdf — French TOC, content body untouched

Tips

  • Indent up to five levels deep — readers show expand/collapse triangles for any level beyond root.
  • Page numbers in the outline are 1-indexed and clamped to the document range automatically — typing 9999 just sets it to the last page.
  • Bookmarks open the page at 'Fit' zoom in most readers; if you need a specific zoom or X/Y, use a dedicated PDF editor.
  • If the source PDF has no outline at all, just start clicking + Add bookmark — the tree builds from scratch.
  • After saving, open the file in any PDF reader and press Ctrl/Cmd+B to confirm the outline pane is now visible.

Frequently Asked Questions

Will my PDF reader see the new bookmarks?▾
Yes. Adobe Acrobat, Apple Preview, Foxit, Chrome's built-in reader, Firefox, and Edge all read the standard outline dictionary that this tool writes.
Can I link a bookmark to a specific X/Y on a page?▾
Not yet — every bookmark uses the /Fit destination (full page). XYZ destinations with custom zoom and offset are on the roadmap.
Does this work on encrypted PDFs?▾
Not directly — unlock the PDF first using the PDF Unlock tool, then the outline editor will load it.
Will my body content change?▾
No. Only the outline dictionary is rewritten. Pages, text, images, and forms are preserved byte-for-byte.
How deep can I nest bookmarks?▾
Up to five levels deep through the indent button — PDF supports unlimited nesting in theory but readers render deeper trees inconsistently.
Can I bulk-edit bookmark titles via find/replace?▾
Not in the current UI — edit them individually. For very large outlines, consider scripting via pdf-lib directly.
Is the document uploaded to your server?▾
Never. Both reading the outline (pdf.js) and writing the new one (pdf-lib) happen entirely in your browser.
Why does my saved PDF open without the bookmarks pane visible?▾
Some readers ignore the PageMode hint by default. Press Ctrl/Cmd+B (Acrobat) or click View → Bookmarks (Preview) to open the pane.

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Glossary

Outline
PDF's official term for what most users call 'bookmarks' — a hierarchical tree of navigation entries shown in the reader's side pane.
PDFOutlineDict
The dictionary in a PDF's catalog that holds /First, /Last, /Count, and references to each outline entry.
PageMode
A catalog entry that tells PDF readers how to open the file — UseOutlines means 'show the bookmarks pane'.
Destination
The target a bookmark jumps to — typically a page reference plus a zoom hint (here, /Fit means fit-to-window).
Hierarchy
The parent/child relationships between outline entries that produce expand/collapse arrows in PDF readers.
AcroForm
Unrelated to outlines — interactive form fields. Outline editing does not affect form field content.