When do you need to merge?
When sending an application made of several documents, collecting a month of invoices, or joining scattered study chapters. One file is easier to send, print and archive than ten.
Merging steps
Open Merge PDF, add all the files, and reorder them with the arrows so the list order matches the page order you want, then press the button and download. Everything happens in your browser without uploading your files.
After merging: cleanup
You may find a blank page or a duplicate cover; remove them with Delete PDF Pages. If you need to change page order afterwards, use Organize PDF Pages and type the new order such as 3,1,2.
Common mistakes
Do not try to merge a password-protected file before removing its protection. And check the result before deleting your originals; the tools never alter your source files, but keeping them is wise.