Jobs that call for one PDF instead of many
Merging is one of the most common PDF chores, usually because the person on the other end wants a single attachment:
- A job application where the portal accepts one file: cover letter, CV and certificates in that order.
- An expense claim with a summary sheet followed by a dozen receipts saved as separate PDFs.
- A visa or rental application that asks for a passport scan, bank statements and an employment letter together.
- Monthly invoices or statements collected into one file per year for the accountant.
- Chapters exported separately from a word processor that need to become one manuscript.
What happens to your pages
The tool reads each file and copies its pages, unchanged, into a new document. Nothing is re-rendered or re-compressed:
- Text stays selectable and searchable.
- Images keep their original quality.
- Each page keeps its own size and orientation, so A4 and US Letter pages, or portrait and landscape pages, can sit side by side in the result.
- Fonts and images travel with the pages that use them.
Because nothing is re-encoded, the merged file is roughly the sum of the inputs. Merging three 4 MB scans gives a file of around 12 MB. If two source files embed the same font, it is stored twice, so the total can be slightly above the sum.
The result is always named merged.pdf. Rename it to something descriptive before sending; "Smith_application_2026.pdf" tells the reader far more.
Getting the order right
Files are combined in the order of the numbered list under the drop area. New files are added to the end, whether you drop them all at once or one at a time.
- Drag a row by its handle to move it anywhere in the list.
- Use the up and down arrows for one-step moves, which is easier on a touchscreen.
- Remove a wrong file with the cross; the rest keep their order.
The Merge button appears once at least two files are in the list. If you change the order or add a file after merging, the previous result is discarded, and you merge again.
Order within each file never changes. If one source PDF has its own pages in the wrong sequence, or a page you do not want, fix that file first with split PDF or by removing pages, then merge.
Naming source files with a number prefix such as 01-cover.pdf, 02-cv.pdf before dropping them makes it easy to check the order at a glance.
What does not come along
Only pages are copied. Anything that belongs to the document as a whole rather than to a page is left behind:
- Bookmarks and the outline panel. The merged file opens without a table of contents in the sidebar.
- Document properties. Title, author and keywords from the sources are not kept.
- Internal navigation. A "go to page 5" link or a clickable table of contents inside one source may stop pointing to the right place, because page 5 of that file is now page 23 of the result.
- Interactive forms. Fill-in fields may lose their behaviour, especially when two sources use fields with the same names. If you need the entered values, fill the forms and print them to PDF before merging.
- Attachments and scripts embedded at document level.
Visible page content, including filled-in values that are already part of the page, carries over as it looks.
Problems you may run into
- One file is refused as password-protected. Encrypted PDFs cannot be merged. Remove the protection with Unlock PDF using the password you have, then merge the unlocked copy.
- The result is too large to send. Merging does not shrink anything. Run the merged file through compress PDF, or compress the image-heavy sources before merging.
- Readers lose track of where each part begins. Add running numbers afterwards with add page numbers, so you can refer to "page 14" in a cover email.
Each file can be up to 100 MB. Everything happens on your device, which matters for exactly the kind of paperwork people merge most often: IDs, bank statements and contracts.