Merging PDFs: What Happens to Bookmarks, Links and Forms

How to merge PDFs in your browser

1. Open the Merge PDF tool.
2. Drop all the PDFs you want to combine, in any order.
3. Drag to reorder them so the pages come out in the sequence you want.
4. Click Merge and download the single combined PDF.

What actually happens when PDFs merge

Merging copies every page from each source document, in order, into one new PDF. Nothing is re-rendered or re-compressed, so the pages in the merged file are pixel-for-pixel identical to the originals. That also means merging is fast even for large documents: it is a reorganisation, not a conversion.

What happens to bookmarks, links and form fields

Page content always survives a merge intact, but the extras that live outside the pages behave differently, and it is worth knowing which is which before you send the combined file.

• Bookmarks (the outline panel) are not carried over. They belong to the document as a whole rather than to individual pages, so the merged file starts with no outline. If navigation matters, add a contents page or re-create bookmarks in a desktop editor afterwards.
• Web links keep working, because a link to a website is attached to the page it sits on and travels with that page.
• Internal links that jump to another page of the same document can break, since the page they pointed to now sits at a different position in a different file.
• Fillable form fields are the most fragile. Their visible boxes copy across, but the form definition that makes them fillable is document-level, so fields may stop being editable. Fill and flatten forms first, then merge.

A quick check after merging

1. Scroll the page thumbnails to confirm the order and that no document was skipped.
2. Click one internal link and one web link to see which still work.
3. If any source had form fields, confirm the entries are visible, or flatten before merging next time.
4. Check the file size before emailing: merging adds sizes together, so a large result may need compressing.

The privacy angle most people skip

PDFs being merged are often exactly the documents you least want on a stranger’s server: contracts, statements, medical records, ID scans. A browser-based merge keeps every page on your own device, because the combining happens locally in your browser tab rather than after an upload.

After merging: common follow-ups

Two tasks commonly follow a merge. If the combined file is too large to email, compress it. If you merged more than needed, split the document or remove specific pages. All three run in the same browser-based toolkit.