Tiny Online Tools
What this tool is for
A PDF's outline — the bookmark tree in a reader's sidebar — is the only navigation a long document has. This editor loads the outline that is already in the file, shows it as a real tree, and writes it back. It is not a text box you paste a list into; it is a structural editor.
What you can change
- Order and nesting. Drag a row to move it, or use the arrow and indent buttons, which do the same job from the keyboard. Moving a row takes its children with it.
- Titles and target pages. Type a new title, or a new page number.
- Appearance. Bold, italic and a colour, written as the
/Fflag bits and the/Carray. Acrobat honours them; several other readers do not. - Open or collapsed. The sign of
/Countdecides whether a branch starts expanded.
What it preserves
A bookmark can point at far more than "page 4". It can carry a scroll position and zoom, a named destination, or a URL. If you do not change a bookmark's page, this tool reuses that original destination object verbatim instead of replacing it with a generic top-of-page link. Only rows you retarget, duplicate or create get a fresh destination.
Generate from headings
If the file has no outline at all, the tool can propose one. It groups each page's text into visual lines, takes the median glyph height as the body size, and treats lines set noticeably larger than that as headings, mapping the distinct sizes onto nesting levels. That is inference from type size, not a tagged structure — read the result before you write it.
Verification
After saving, the written bytes are reopened and the outline is read back through a completely separate parser. The tool reports the tree the file actually reports, so a wrong /Prev or /Count shows up here rather than in your reader.
Privacy
The file is opened, edited and saved entirely inside your browser. Nothing is uploaded, and no outline text leaves the page.