Free Online PDF Merger — Merge PDFs in Your Browser
⭐ Drag-and-drop reorder · See file sizes before merging · Rename output · 100% private
Combine multiple PDF files into one. No upload to any server. Drag-and-drop reorder. See exact file sizes before and after merge. 100% free, no sign-up.
Merge PDFs Now →Why Our PDF Merger Is Different
Most online PDF mergers require you to upload files to a remote server. This means your documents travel across the internet, sit on someone else's hard drive, and potentially expose sensitive information. Our merger works entirely in your browser using WebAssembly technology — your files never leave your device.
Drag-and-Drop Reorder
Unlike basic tools that only merge in upload order, our PDF merger lets you rearrange pages by simply dragging files with your mouse. Click and hold any file, move it to the desired position, and release. A green indicator line shows exactly where it will land. You can also use the move buttons (top, up, down, bottom) for precise control, or sort by name, time, or file size with one click.
See File Sizes Before and After
Before merging, you see the total input size of all selected files. After merging, the page displays the merged file size right next to the page count — so you know exactly what you're downloading. Our tool even estimates how much space is saved during the merge process (typically 10-30% due to font and metadata deduplication).
Rename Before Downloading
Don't settle for a generic filename like "merged.pdf". Our tool lets you rename the output file right on the page before downloading. Just click "Rename" next to the download button, type your preferred name, and download — no extra steps needed.
Multi-Select with Ctrl/Shift
Need to move multiple files at once? Hold Ctrl and click to select individual files, or Shift-click to select a range. Then drag them as a group to reorder, or use the move buttons to reposition them all at once.
Frequently Asked Questions
Are my PDF files safe?
Yes — all processing happens locally in your browser. Files are never uploaded to any server. You can verify this by disconnecting your internet after loading the page — the merger still works.
How many PDFs can I merge?
There's no hard limit. The practical limit depends on your device's memory, but most computers handle 20+ files easily.
Does merging reduce file size?
Often yes. When multiple PDFs share the same fonts, the merger deduplicates them, typically saving 10-30% compared to the sum of input sizes.
Can I merge on mobile?
Yes — the tool works on phones and tablets. Use the move buttons for reordering on touch screens.