PDF Mergy is a free web-based application that allows you to merge PDF files with a simple drag and drop interface. This app provides a convenient way to merge PDF files in a few easy steps. You can select the files you want to merge from your computer or drag and drop them onto the app. Once you have uploaded the files, you can arrange them in the desired order using drag and drop. The resulting merged PDF file will contain all documents in the order as they appear on the screen.

It is worth noting that in order to process your files, they will be uploaded to a remote server. However, the files are uploaded and stored only for the purpose of being merged. A few minutes after processing, all files are deleted permanently from the remote system. Additionally, this app uses a secure SSL connection to prevent eavesdropping, ensuring the safety and privacy of your files.