How to Merge PDF Files Locally in a Browser Without Uploading Them

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Merging PDF files is a routine task, but most free online tools require uploading documents to a server, which poses a privacy risk for sensitive files such as contracts, medical records, or financial documents. Browser-based PDF merger tools process files entirely on the user's device, meaning no data is transmitted, stored, or exposed to third parties. Users can drag and drop files, arrange them in the desired order, and download the combined result without needing an internet connection after the page loads. However, there are practical considerations: password-protected files must be unlocked beforehand, form fields with identical names may conflict, and mixed page sizes will be preserved as-is in the output. The final merged file size is roughly the sum of all inputs, so compression may be advisable for large documents.

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