在线合并 PDF 文件 — 免费且私密 |易工具

How to Merge PDF Files

Upload your PDFs

Drag and drop multiple PDF files or click to select them from your device. All files stay in your browser — nothing is uploaded.

Arrange the order

Use the arrow buttons to reorder your files. The PDFs will be merged in the order shown on screen.

Download the merged PDF

Click "Merge PDF" and download a single combined file containing all your documents in the chosen order.

Why use FyleTools to merge PDFs?

100% Private

Your files never leave your device. All merging happens in your browser using WebAssembly — no server uploads, no third-party access.

Free & Unlimited

No registration, no file limits, no watermarks. Merge as many PDFs as you need, completely free.

Preserves Quality

The merged PDF retains the original quality, fonts, and formatting of all source documents. No re-encoding or compression.

Frequently Asked Questions

Are my PDFs uploaded to a server?

No. FyleTools processes everything directly in your browser using WebAssembly technology. Your files never leave your device, making it completely safe for sensitive documents.

Is there a limit on how many PDFs I can merge?

There is no fixed limit. Since processing happens in your browser, the practical limit depends on your device's available memory. Most devices handle dozens of files without issues.

Does merging affect the quality of my PDFs?

No. The merge operation combines the original PDF data without re-encoding. All text, images, fonts, and formatting are preserved exactly as they were.

Can I change the order of the pages?

Yes. Use the arrow buttons to reorder files before merging. For more advanced page manipulation, try our Organize PDF tool which lets you reorder individual pages.

Are bookmarks and links preserved?

Basic PDF structure is preserved during merging. Complex features like interactive forms may need to be verified after merging.

Does this work on mobile devices?

Yes. Upload PDFs from your phone's file manager and merge them directly in your browser. No app installation required.

Can I merge password-protected PDFs?

Protected PDFs must be unlocked first. Use our Unlock PDF tool to remove the password, then merge the unprotected files.

Merge PDF