100% PrivateDrag to ReorderUp to 20 Files

How It Works

1

Add Files

Drop or select 2-20 PDF files.

2

Reorder

Drag files to arrange them in the desired order.

3

Merge & Download

Click Merge and download the combined PDF.

Frequently Asked Questions

How do I merge multiple PDF files into one?
Click the dropzone or drag PDF files into it. You can add up to 20 files. Drag to reorder them, then click Merge. The combined PDF downloads instantly.
Can I reorder pages before merging?
Yes. After adding files, drag and drop them in the list to change the order. The merged PDF will follow the order you set. Each file shows its page count so you can plan the layout.
What is the maximum number of files I can merge?
You can merge up to 20 PDF files at once. There is no strict page limit, but very large documents may take longer to process in the browser.
Does merging change the quality of my PDFs?
No. Merging combines the original pages without re-encoding or compressing. Text, images, and formatting remain identical to the source files.
What is the difference between merge and append?
They are the same operation. Merge (or append) places all pages from multiple PDFs into a single file in sequence. This tool lets you control the exact order before combining.
Share:

About Merge PDF

What this tool does

These tools let you merge multiple PDFs into one document, split a PDF into individual pages, compress large files for email, add page numbers, watermarks, or passwords, and convert between PDF and image formats.

Why use this tool

PDFs are the standard for invoices, contracts, reports, and forms. Being able to manipulate them without installing Acrobat or uploading to a third-party site saves time and protects confidential data. Everything processes client-side using pdf-lib and PDF.js.

How it works

The browser reads the PDF binary, parses its page tree and content streams, then performs the requested operation: re-ordering pages for a merge, extracting a range for a split, or re-compressing images for size reduction. The result is assembled into a new PDF that you download directly.

Pro tip

For the best compression, combine image downsampling with font subsetting. If your PDF is mostly scanned pages, converting to grayscale first can cut file size by half.

Deep Dive: Related Research

PDF Tools Benchmark 2026: 15 Tools Compared on Compression, Speed, and Privacy

11,000 words · 22 min read

The Complete Guide to File Formats: Every Format Explained, Compared & Benchmarked (2026)

52,000 words · 65 min read

Part of these workflows

PDF Document Preparation

3 steps

Explore More

Love this tool? Explore 12467+ more

Free online tools for images, PDFs, text, code, and more. All running in your browser.

Explore All Tools