Merging PDF files is one of the most common document tasks, yet most online tools require uploading your sensitive files to unknown servers. This guide explains how RefineDoc performs 100% client-side merging using WebAssembly, keeping your data completely private.
Why Client-Side Merging Matters
Traditional PDF mergers upload your files to a cloud server, process them, then delete after a few hours. This creates potential security risks, especially for financial reports, legal documents, or personal information. With RefineDoc, your files never leave your browser. The merging engine runs locally using WebAssembly, providing desktop-grade performance without any data transfer.
Security Fact:
Over 60% of cloud-based PDF tools have been found to retain user data for up to 30 days. RefineDoc retains zero bytes because nothing is uploaded.
Step-by-Step: Merging PDFs in RefineDoc
- Drag & drop your PDF files into the merge workspace (you can add up to 20 files).
- Reorder pages by dragging thumbnails β perfect for combining specific sections from different documents.
- Click "Merge" β the process takes seconds, even for large files, thanks to WASM acceleration.
- Download your merged PDF instantly β no watermarks, no quality loss.
RefineDoc vs. Traditional Tools
| Feature | RefineDoc | Smallpdf | ILovePDF |
|---|---|---|---|
| Privacy | 100% Local | Cloud Upload | Cloud Upload |
| File Size Limit | Unlimited (RAM-based) | 100 MB | 50 MB |
| Watermark | None | Free tier watermark | Free tier watermark |
| Offline Mode | Yes | No | No |
Pro Tips for Seamless Merging
- Check page orientation β ensure all source PDFs have the same orientation (portrait/landscape) or use our rotate tool beforehand.
- Reduce file size first β if your PDFs are very large, compress them individually before merging for faster processing.
- Use bookmarks β RefineDoc preserves original bookmarks and hyperlinks when merging, maintaining document navigation.
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