How do I merge PDF files online for free?

Upload two or more PDF files using the drop zone above, arrange them in the order you want, then click Merge & Download PDF. The merged file downloads instantly to your device.

Is my PDF data safe when using this tool?

Yes. All processing happens entirely inside your browser using the pdf-lib JavaScript library. Your files are never uploaded to any server, so your data remains completely private.

Is there a file size limit for merging PDFs?

There is no hard limit set by this tool. Practical limits depend on your device's available RAM. For very large PDFs (over 100 MB each), performance depends on your browser and hardware.

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📎 PDF Merger

Combine multiple PDF files into one. Drag, reorder, and download instantly — no upload, no server.

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Add PDF Files

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Drop PDF files here

or click to browse — you can add multiple files

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Files to Merge

No PDF files added yet. Drop files above or click to browse.

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About This Tool

This tool uses pdf-lib, a pure JavaScript PDF library, to merge your files entirely inside your browser. No files are ever sent to any server — your PDFs stay on your device. You can add as many files as you like, drag to reorder them, and download the merged result instantly.

📎 Combine unlimited PDFs

↕ Reorder before merging

✓ Zero server transmission