How to use the Merge PDF
- Pick at least two PDFs, or drag in the folder that holds them.
- Arrange them with the up and down arrows. The number beside each file shows where it will land.
- If the result will be printed on both sides, open More settings and switch on the blank page option.
- Press Merge and save the combined document.
Building a submission pack
A typical pack is a cover letter, a filled-in form, a copy of an ID and a few supporting statements. Put them in the order the checklist asks for, merge once, and the reviewer gets one file that reads front to back.
Pages are carried over as they are, not printed to an image, so typed text in the letter stays searchable and the scans keep their resolution. The merged size is close to the sum of the inputs, because fonts that appear in several files are kept once per file.
Double-sided printing and forms
If one document ends on an odd page, the next would begin on the back of that sheet. The blank page option adds an empty page of matching size after each such file, except the final one, so every document starts on a fresh sheet.
Outline bookmarks from the inputs are not kept, and interactive form fields may stop being editable after merging. Flatten a filled form first if its answers have to survive.
Questions
Do my documents go to a server?
No. Merging happens in the browser tab with pdf-lib, and the result is written straight to your downloads.
Is there a cap on files or pages?
No fixed one. The limit is the memory of your device: a laptop copes with hundreds of files, a phone with fewer.
One of my PDFs asks for a password. Can it be merged?
Not directly. Remove the open password with Unlock PDF first. Files that only restrict printing or copying merge without that step.