How is this different from other online PDF tools?

Most online PDF tools send your files to a remote server for processing. This tool processes everything locally in your browser using client-side JavaScript. Your files are never transmitted to any server, which means your document content stays entirely under your control.

Are my PDF files uploaded?

No. Your files are read directly by your browser. Your files are never transmitted over the network. The tool works entirely within the browser tab you have open.

Can I verify that files are not uploaded?

Yes. Open your browser's developer tools (F12), go to the Network tab, and watch for any outgoing requests while using the tool. You will see no file data leave your browser. The site may record an anonymous page-view count, which never includes your files and can be disabled.

Does this tool work offline?

Yes, once the page has loaded the tool processes your files entirely in your browser; tool functionality needs no network connection. You can disconnect from the internet and continue using it.

What happens when I refresh the page?

Because nothing is stored on a server, refreshing the page clears your current session. Any files you had selected will need to be selected again.

Does this tool store my files?

No. Files are held in browser memory only for as long as the page is open. Closing or refreshing the page discards them. Nothing is written to disk by the tool, and nothing is sent to a server.

Can this tool unlock password-protected PDFs?

No. This tool does not attempt to remove or bypass PDF password protection. If you know the password, the Unlock PDF tool on this site can remove it locally; then this tool can process the file.

What technologies does this tool use?

This tool uses client-side JavaScript and pdf-lib for local PDF structure editing. Processing runs synchronously on the main thread within your browser.

Does this tool use WebAssembly?

No. This tool uses client-side JavaScript and pdf-lib for local PDF structure editing. No WebAssembly is involved.

How do I merge PDFs with this tool?

Pick two or more PDF files from your device, then press the Merge button. The tool reads each file in your browser, copies every page into one combined document, and offers it back as a download named merged.pdf.

What order are the pages in the merged file?

Pages follow the order in which the files were selected: all pages of the first file come first, then all pages of the second, and so on. The tool combines whole documents and does not let you reorder or cherry-pick individual pages, so arrange your files before merging.

Why won't a password-protected PDF merge?

The tool loads each PDF locally with pdf-lib and stops with an error if any file is encrypted, since it does not decrypt protected documents. Remove or supply the password in your PDF reader and save an unprotected copy first, then merge that copy.

Does the Merge PDF tool cost anything to use?

Merging your PDF files here is completely free — no account, no sign-up, and no limit on how many files or how often you combine them, and it always will be. Every file you select is read and joined entirely inside your own browser using pdf-lib, so your documents are never sent to a server or anyone else's infrastructure.

Merge PDF Files Privately — Everything Stays in Your Browser

Select two or more PDF files, click Merge, and download the combined PDF — all processing happens locally in your browser without any file upload.

Quick answer

What it does: Select two or more PDF files, click Merge, and download the combined PDF — all processing happens locally in your browser without any file upload.
Free?: Yes — 100% free, no account or sign-up.
Files uploaded?: No — everything is processed in your browser.
Works offline?: Yes — once the page has loaded.
Best for: Combining several invoices or boarding passes into one file before printing or emailing.
Good to know: Very large PDFs (hundreds of megabytes) may be slow to process depending on available device memory.

How it works

Select two or more PDF files from your device using the file picker.
Each file is read into browser memory using the FileReader API — no data leaves your browser.
pdf-lib loads each PDF document in turn and copies every page into a new, combined PDF.
The finished PDF is offered as a download directly from your browser.
All temporary file data is released from memory once the download is complete.

When to use this tool

Combining several invoices or boarding passes into one file before printing or emailing.
Gathering all chapters of a report into a single PDF to hand off to a client or publisher.
Merging multiple signed contract pages into one PDF for record-keeping.
Note: whole documents only — to pick specific pages, use Split first to extract them, then Merge.

Frequently asked questions

How is this different from other online PDF tools?: Most online PDF tools send your files to a remote server for processing. This tool processes everything locally in your browser using client-side JavaScript. Your files are never transmitted to any server, which means your document content stays entirely under your control.
Are my PDF files uploaded?: No. Your files are read directly by your browser. Your files are never transmitted over the network. The tool works entirely within the browser tab you have open.
Can I verify that files are not uploaded?: Yes. Open your browser's developer tools (F12), go to the Network tab, and watch for any outgoing requests while using the tool. You will see no file data leave your browser. The site may record an anonymous page-view count, which never includes your files and can be disabled.
Does this tool work offline?: Yes, once the page has loaded the tool processes your files entirely in your browser; tool functionality needs no network connection. You can disconnect from the internet and continue using it.
What happens when I refresh the page?: Because nothing is stored on a server, refreshing the page clears your current session. Any files you had selected will need to be selected again.
Does this tool store my files?: No. Files are held in browser memory only for as long as the page is open. Closing or refreshing the page discards them. Nothing is written to disk by the tool, and nothing is sent to a server.
Can this tool unlock password-protected PDFs?: No. This tool does not attempt to remove or bypass PDF password protection. If you know the password, the Unlock PDF tool on this site can remove it locally; then this tool can process the file.
What technologies does this tool use?: This tool uses client-side JavaScript and pdf-lib for local PDF structure editing. Processing runs synchronously on the main thread within your browser.
Does this tool use WebAssembly?: No. This tool uses client-side JavaScript and pdf-lib for local PDF structure editing. No WebAssembly is involved.
How do I merge PDFs with this tool?: Pick two or more PDF files from your device, then press the Merge button. The tool reads each file in your browser, copies every page into one combined document, and offers it back as a download named merged.pdf.
What order are the pages in the merged file?: Pages follow the order in which the files were selected: all pages of the first file come first, then all pages of the second, and so on. The tool combines whole documents and does not let you reorder or cherry-pick individual pages, so arrange your files before merging.
Why won't a password-protected PDF merge?: The tool loads each PDF locally with pdf-lib and stops with an error if any file is encrypted, since it does not decrypt protected documents. Remove or supply the password in your PDF reader and save an unprotected copy first, then merge that copy.
Does the Merge PDF tool cost anything to use?: Merging your PDF files here is completely free — no account, no sign-up, and no limit on how many files or how often you combine them, and it always will be. Every file you select is read and joined entirely inside your own browser using pdf-lib, so your documents are never sent to a server or anyone else's infrastructure.