How do I merge PDF files online for free?

Add your PDF files using the button or by dragging them in, arrange them in the desired order using the arrow buttons, then click Merge. The merged PDF downloads directly to your computer.

Why is this tool free?

inyourbrowser.com provides free in-browser tools. Because all processing happens in your browser, there are no processing costs to pass on to you.

Does merging PDFs reduce quality?

Pages are copied from the source PDFs without re-encoding, so there is no quality loss to text, images, or any other content.

Can I merge password-protected PDFs?

The tool merges PDFs that are not encrypted. An encrypted file, including one that opens without a password but restricts editing or printing, is named and left out of the list. Remove the protection in your PDF viewer, then add the file again.

What browsers are supported?

Any modern browser. Chrome, Firefox, Edge, and Safari on desktop and mobile. No extensions or plugins are needed.

Merge PDF Files Online

Add your PDFs, arrange them with the arrow buttons, and click Merge to download one combined file named merged.pdf. Pages are copied as they are, so text stays selectable and images keep their quality. All processing runs in your browser.

Drop PDF files here or click to browse

You can add multiple files

How it works

When you click Merge, pdf-lib loads each PDF you added and copies its pages, in the order shown in the list, into an in-memory output document, then the resulting bytes are wrapped in a Blob and offered for download. The whole pipeline runs in the page you have open, which is why merging starts as soon as you click without any upload wait.

Processing runs in your browser

All merging happens inside your browser tab. pdf-lib combines your PDFs entirely in memory; our servers are not involved at any point. You can confirm this yourself in your browser's DevTools Network tab.

Related operations

For pulling out a single section before merging, try split PDF. To straighten sideways scans first, use rotate PDF. For shrinking the combined file, see compress PDF.

Frequently asked questions

How do I merge PDF files online for free?: Add your PDF files using the button or by dragging them in, arrange them in the desired order using the arrow buttons, then click Merge. The merged PDF downloads directly to your computer.
Why is this tool free?: inyourbrowser.com provides free in-browser tools. Because all processing happens in your browser, there are no processing costs to pass on to you.
Does merging PDFs reduce quality?: Pages are copied from the source PDFs without re-encoding, so there is no quality loss to text, images, or any other content.
Can I merge password-protected PDFs?: The tool merges PDFs that are not encrypted. An encrypted file, including one that opens without a password but restricts editing or printing, is named and left out of the list. Remove the protection in your PDF viewer, then add the file again.
What browsers are supported?: Any modern browser. Chrome, Firefox, Edge, and Safari on desktop and mobile. No extensions or plugins are needed.

Last reviewed September 30, 2026

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