Published February 18, 2025 · 5 min read

How to Merge PDF Files Free Online

Need to combine multiple PDF documents into a single file? Whether you're assembling a report from separate chapters, merging scanned pages, or combining invoices for your records, merging PDFs is one of the most common document tasks. The good news: you can do it for free, in seconds, without uploading your files anywhere.

Why Merge PDF Files?

There are countless situations where combining PDFs makes life easier:

How to Merge PDFs in 3 Simple Steps

  1. Open the tool — Go to the free PDF merger on This 2 That.
  2. Add your files — Drag and drop multiple PDF files onto the page, or click to browse. You can reorder them as needed.
  3. Download the merged PDF — Click merge and your combined PDF is ready instantly. Download it directly to your device.

The entire process happens in your browser. Your PDF files are never uploaded to any server — they're processed locally using JavaScript, which means your documents remain completely private.

Combine your PDFs now — free, private, no account needed.

Merge PDFs Free →

The Privacy Problem with Online PDF Tools

Most online PDF mergers work by uploading your files to their servers. Think about what that means: your contracts, tax documents, medical records, or business reports are being transmitted to and stored on someone else's computer. Even if they promise to delete files after processing, you have no way to verify that.

Some popular PDF tools have been caught retaining user files, sharing data with third parties, or using uploaded documents to train AI models. For sensitive documents, this is a serious risk.

This 2 That eliminates this risk entirely. Because the merger runs in your browser, your files never leave your device. There's no upload, no server-side processing, and no data retention. It's the same result with zero privacy trade-off.

Tips for Better PDF Merging

What About Password-Protected PDFs?

If any of your PDF files are password-protected, you'll need to unlock them before merging. Most browser-based tools can't process encrypted PDFs directly. Remove the password protection first (you'll need the password, of course), then merge the unprotected files.

Merging vs. Splitting PDFs

Sometimes you need the opposite operation — extracting specific pages from a large PDF. If that's what you're after, check out our PDF splitter tool. It lets you extract individual pages or page ranges from a PDF, and like all our tools, it works entirely in your browser.

Other PDF and Document Tools

Every tool on This 2 That processes files locally in your browser. Convert anything, upload nothing.