Short, direct answers to the questions people ask most about combining PDF files. For the full walkthrough, see the complete PDF Merger guide.
The basics
How do I merge PDF files into one document? Add two or more PDFs, drag them into order, click merge, and download. The Aizen PDF Merger does this in your browser with no upload.
Is it safe to merge PDFs online? Only if the tool does not upload your files. The Aizen PDF Merger works locally, so documents never leave your device.
Can I merge PDFs for free? Yes — free, no sign-up, no watermark, no server-imposed limit.
Does merging reduce quality? No. Pages are copied as-is; text stays selectable and images keep their resolution.
Order and pages
Can I change the order before merging? Yes. Drag files into position first; pages follow that order.
Can I merge only certain pages from each PDF? Extract them with Split PDF first, then merge the extracts.
How is merging different from Image to PDF? Merging joins existing PDFs; Image to PDF builds a PDF from image files.
Files, limits and formats
Can I merge password-protected PDFs? Unlock them first — encrypted files must be readable to merge.
Is there a limit to how many PDFs I can combine? No server limit; your device's memory is the practical cap.
Can I merge scanned PDFs? Yes. Scanned pages are image-based PDFs and merge normally.
Will the merged file be very large? Roughly the sum of the originals. Compress it if needed.
Do bookmarks and form fields survive? Page content is preserved; some complex interactive features may not carry over.
Devices and tools
Can I merge PDFs on my phone? Yes, in any modern mobile browser — no app required.
Do I need Adobe Acrobat? No. A free browser-based merger does the core job.
Does the Aizen PDF Merger add a watermark? No — never.
Why merge instead of sending separate files? One ordered document is easier to email, sign, print and archive.
Ready to combine your files? Open the PDF Merger, or read how to merge PDF files for the step-by-step.