Merge PDF files
Combine multiple PDFs into a single document directly in your browser. Reorder files, then click Merge PDF. Your files are never uploaded — processing runs entirely on your device.
Drop PDF files here
or click to choose files from your device
Accepted: PDF · Multiple files allowed · No upload
How to merge PDF files
- Add your PDFs. Drag files into the drop zone above, or click the zone to browse your device. You can add several files in one go.
- Reorder them. Use the up and down arrows on each file card to set the exact order the merged document should follow.
- Click Merge PDF. The merge runs locally in your browser using WebAssembly. Large files trigger a warning so you can decide whether to continue on that device.
- Download. The merged PDF appears as a download button. Save it wherever you like.
What Merge PDF preserves
- Page size, orientation and page rotation
- Vector text and image quality
- Internal links and bookmarks that already exist inside each source file
- Standard document metadata from the first file
Interactive AcroForm fields are preserved for most PDFs, but merging files that share identical field names can cause those fields to merge. If your files contain fillable forms you may want to flatten them first with the Flatten PDF tool.
Privacy and security
Merge PDF runs entirely inside your browser. Files are read from disk, processed by JavaScript and WebAssembly running on your device, and handed back to you as a downloadable Blob. Nothing is uploaded, nothing is logged, and nothing survives after you close the tab.
Known limitations
- Passwords cannot be bypassed. If a source PDF is encrypted, you must supply the password on that file first (via Unlock PDF) before merging.
- Merging several very large PDFs on a low-memory phone may fail. The tool warns you before you start.
- Digital signatures inside source files are invalidated as soon as the file is merged, because the document bytes change.