Choosing pages
Each file has a Pages box. Leave it empty to take every page, or type the pages you want:
1-3, 5takes pages 1, 2, 3 and 5.8-takes page 8 to the end.5-1takes pages 5 to 1, in reverse order.2, 2takes page 2 twice.
Pages are added in the order you write them. If a number is past the last page, the tool tells you how many pages that file has. You can also use this with a single file to pull out or reorder pages.
What is kept
Pages are copied exactly, so text stays selectable and searchable, and images keep their quality. Page sizes are kept too, so an A4 file and a Letter file can sit in the same PDF. Links within pages usually keep working. Bookmarks, form fields that need to stay fillable and digital signatures are not carried over, because a signature only covers the original file.
Password-protected and damaged files
A PDF that needs a password to open cannot be merged, and the tool names the file so you know which one. Open it with the password in your PDF reader, save or print a copy without protection, and add that copy instead. If a file is damaged, opening it in a reader and saving it again often repairs it.
Large files, no upload
Files of up to 50 MB each, and 200 MB in total, are merged on your own device. The PDF library loads only when you press Merge, and the work runs in a background worker, so the page stays responsive. On older phones with little memory, merging very large files may still fail; if it does, merge them in two smaller batches. Your documents are never uploaded, which matters for ID cards, bank statements and contracts.