How to merge PDF files
- Add the PDFs you want to join. They queue up in the order you added them — first file first.
- Check the page order. Every page from every file is shown, so you can drag one to a different spot before merging.
- Drop anything you don't want in the final file. Removing a page here never touches the original.
- Press Export PDF. You get one file containing the pages in the order shown.
Merging is a page-level operation
Most people reach for "merge" when they have a report and its appendix, or a contract and a signed page, and want one file to send. That is exactly what happens here: each source is opened, its pages are lined up, and the result is written as a single document.
Because the merge works at page level, you are not limited to whole files. If the appendix has ten pages and you only want the last two, drop the other eight before exporting — you do not need to split the file first.
What carries over, and what doesn't
Pages from the source PDFs are copied structurally rather than re-rendered, so text stays selectable and ordinary links keep working. Each page also keeps its own size, so an A4 report and an A3 drawing can sit in the same file without one being stretched to match the other.
Document-level metadata and bookmarks come from the first PDF you added that still has pages in the result. They are not merged across files — there is no reliable way to combine two bookmark trees without inventing structure that was never in either document.
Editing and re-exporting a PDF can invalidate an existing digital signature. Your original files are never modified; the merged file is always new.
Frequently asked questions
How many PDFs can I combine at once?
Add as many as you need within the workspace limits: the workspace holds up to 2,000 pages at a time. PDFs have no fixed size limit — very large ones switch to memory-saving previews, and are only refused when the estimated browser memory would be too high. Several documents totalling a few hundred pages work comfortably.
Can I merge only some pages of a file?
Yes. Add the whole PDF, then remove the pages you don't want before exporting. The pages you remove are simply left out of the output.
Are my files uploaded to combine them?
No. The PDF engine runs inside your browser tab, so the file bytes never leave your device. You can keep the network panel open while you work.
Does the merged file keep the bookmarks from both PDFs?
No. Bookmarks and document metadata come from the first PDF that contributes pages. Bookmarks from the other files are not carried over.
Can I add an image while merging?
Yes — images can go into the same file, and each one becomes a page. If most of your sources are images, Combine PDF and Images is the page written for that.