How to combine PDFs into one well-organized file
Merging is useful whenever related documents travel together: an application with its supporting letters, monthly invoices for an accountant, or scanned receipts for an expense claim. A single file is easier to send, easier to review and less likely to have a missing attachment.
What happens to the pages
Pages are copied from each file into a new PDF in the order you set. They are not re-rendered or re-compressed, so text stays selectable and searchable, images keep their resolution, and links on the pages continue to work.
The merged file is roughly the sum of the original file sizes. If the result is too large to email, run it through Compress PDF afterwards.
Files that need attention first
Password-protected PDFs cannot be merged, because their contents are encrypted. The tool tells you which file is locked; open it with its password, save an unlocked copy, and add that copy instead.
Damaged or partially downloaded files are rejected with a message naming the file, so you know which one to replace rather than receiving a merged PDF with blank pages.
Ordering the documents
Drag the files into the sequence a reader expects. A common pattern is a cover letter or summary first, then the main document, then appendices in the order they are referenced. If you need to move individual pages rather than whole files, merge first and then use Reorder Pages on the result.
Tips for merging
- Rename files with a number prefix (01, 02, 03) before uploading so the default order is already correct.
- Rotate sideways scans before merging so every page reads the same way.
- For very large batches, merge in groups of 20–30 files on older phones to avoid running out of memory.