Merge PDF

Combine multiple PDF files into a single document — entirely in your browser.

1
Upload PDFs

Drag and drop or click to select 2 or more PDF files.

2
Arrange Order

Drag files to reorder them however you want.

3
Merge & Download

Click Merge PDFs and your combined file downloads instantly.

Drag & drop PDF files here or click to browse

About the Merge PDF Tool

Merging PDFs is one of the most common document tasks — whether you're combining a resume and cover letter, assembling a multi-section report, bundling invoices, or packaging legal exhibits. ChopFile's merge tool handles all of this directly in your browser, with no file uploads required.

How it works

When you add files and click Merge, ChopFile uses the open-source pdf-lib library running in a Web Worker to copy pages from each source PDF and combine them into a new document. The entire process happens on your device — nothing is sent to any server. Your files stay private from start to finish.

When to use Merge PDF

Tips for best results

Arrange your files in the correct order before clicking Merge — drag the file cards to reorder them. If any pages are rotated incorrectly, use the Rotate PDF tool on individual files first. To extract only specific pages from a source file before merging, use Split PDF. After merging, you can update the document title and author using Edit Metadata.

Frequently Asked Questions

Is it safe to merge PDFs online?

Yes. ChopFile processes everything in your browser. Your files are never uploaded to any server.

How many PDFs can I merge?

There's no hard limit. It depends on your device's memory. Most devices handle dozens of files easily.

Can I reorder the files before merging?

Yes. Drag and drop to rearrange files in the order you want.

Does merging reduce PDF quality?

No. ChopFile copies pages directly without re-rendering, so quality is identical to the originals.

Can I merge password-protected PDFs?

No. You'll need to unlock them first using our Unlock PDF tool, then merge the unlocked files.

What's the maximum file size?

There's no hard limit, but very large files (200MB+) may be slow on devices with limited memory.