Merge PDF Files
Combine multiple PDF documents into a single file. Free, private, and 100% client-side.
Drag & drop PDFs here to combine them
Max file size: 50MB
Select files to begin
How to Merge PDF Files Online (Free & Private)
Merging multiple PDF documents into a single file is essential for organizing reports, combining agreements, or cleaning up your digital workspace.UnitMaster PDF Merger allows free users to combine up to 2 files. Upgrade to Pro for unlimited batch merging and instant processing.
Frequently Asked Questions
How to Merge PDF Files Offline
Merge multiple PDF documents into a single file without uploading them to a cloud server. UnitMaster uses your browser's built-in PDF engine to combine files locally, ensuring 100% privacy for your sensitive contracts, reports, and receipts.
100% Private (No Server Uploads)
Your files never leave your device. All processing happens locally in your browser.
Unlimited Files & Size
Since it runs on your machine, there are no artificial limits on file count or size.
Drag & Drop Reordering
Easily arrange your PDF pages visually before merging them.
Works Offline (PWA Support)
Install UnitMaster as an app and merge PDFs even without an internet connection.
Why choose UnitMaster?
- Your data never leaves your device.
- Arrange pages exactly how you want them.
- Instant processing - no upload wait times.
- Free for commercial use.