There is no hard limit on the number of files. You can add as many PDFs as you need. Keep in mind that merging a very large number of PDFs or files with many pages may be slow and consume significant browser memory. For best performance, try to keep the total combined file size under 100 MB.
The files are merged in the order they appear in the file list, which is the order you added them. To change the order, remove the files and re-add them in the desired sequence. Future versions may add drag-and-drop reordering. Plan your order before adding for the most efficient workflow.
No. All merging is performed locally in your browser using the pdf-lib JavaScript library. Your files are never transmitted over the internet. This makes the tool completely safe for confidential documents such as contracts, financial statements, and personal records.