How to merge PDF files online free
Drop two or more PDF files onto the page. They appear in a list with move-up and move-down buttons — arrange them in the order you want the pages to appear, then press Merge PDFs. The tool stitches every page of every file into one PDF, in your chosen order, and hands you a single download. Scanned documents, invoices, lecture slides, rental applications: anything that arrived as separate PDFs becomes one file in under a minute.
Are my PDFs uploaded to a server?
No. Merging runs entirely in your browser using the pdf-lib library loaded from a public CDN. Your documents never leave your device, which makes this safe for contracts, medical forms, and anything else you would not email to a stranger. Close the tab and nothing remains — there is no server copy because there was never an upload.
Will merging change my PDF pages?
Pages are copied as-is: text, images, fonts and page sizes are preserved exactly as they were in the source files. The tool does not recompress images or alter layouts, so a scanned page looks identical in the merged file. One honest limit: password-protected PDFs cannot be opened by the browser and will be skipped with an error message — remove the password first if you own the document.
What is the file size of the merged PDF?
Roughly the sum of the inputs, since pages are copied without recompression. If the merged file is too large to email, compress the images inside the source PDFs first, or split the result with our Split PDF tool. For image-only PDFs built from photos, consider our JPG to PDF tool instead, which gives you quality control at creation time.