How to Merge PDF Files Online
ZenBuild's PDF editor lets you combine multiple PDF files into a single document right in your browser. Open your first file, drop additional PDFs onto the canvas to merge them, reorder pages, and download the result. Your files never leave your device.
Step-by-step guide
Open your first PDF in the editor
Go to Edit PDF and upload your main PDF file by dragging it onto the drop area or clicking to browse. The editor loads the document with a page thumbnail sidebar on the left and a full canvas view in the center.
Drop additional PDFs onto the canvas
Drag and drop another PDF file directly onto the canvas area. The new pages are appended after the existing pages. Repeat for as many files as you need to merge. You can see all pages in the thumbnail sidebar on the left and drag thumbnails to reorder pages.
Download the merged PDF
Once all files are combined and pages are in the right order, click the Download button in the toolbar. The editor merges everything into a single PDF and downloads it. You can also use the thumbnail sidebar to delete any pages you don't need before downloading.
Tools for this task
Merge PDF
Combine multiple PDF files into one document. Drag and drop to reorder pages before merging.
Split PDF
Extract specific pages or split a PDF into multiple files. Select exactly which pages you need.
Compress PDF
Reduce PDF file size without losing quality. Perfect for email attachments and faster uploads.
Tips
- Drag page thumbnails in the left sidebar to reorder pages after merging
- Right-click a thumbnail and choose 'Delete Page' to remove unwanted pages
- For large documents, use the Tools drawer to compress the merged PDF before downloading
- Use the split tool in the Tools drawer if you only need specific pages from the result
Frequently asked questions
Is there a file size limit for merging?
Starter plan users can merge files up to 10MB each. Pro and Business plans support files up to 50MB and 100MB respectively.
Does merging affect PDF quality?
No. The merge process combines pages without re-encoding, so the original quality of text, images, and formatting is fully preserved.
Can I merge password-protected PDFs?
You'll need to decrypt protected PDFs first using the Encrypt/Decrypt tool, then merge the unlocked files.
Related guides
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