Will merging reduce the quality of my PDF?

No. Pages are copied into the new file as-is; they are not re-rendered, rasterized, or compressed during a merge.

Does this work without an internet connection?

You need an internet connection to load the page and the pdf-lib script the first time. Once loaded, the merge itself does not require network access.

Merge PDF Files Online — Free

Runs in your browser. Files are never uploaded to a server.

1. Select PDF files

Choose two or more PDF documents to combine. They stay on your device.

2. Merge

Your browser combines the pages locally — nothing leaves your device.

📘 More PDF guides on our blog

Local only

Processed in your browser's memory. Nothing is uploaded — check your Network tab yourself.

No queue

No upload/download round trip, so it starts immediately.

Any modern browser

Works on Chrome, Firefox, Safari, and Edge — desktop or mobile.

How PDF merging works on PDFTeq

This tool uses pdf-lib, an open-source JavaScript library, to read each selected file directly into your browser's memory, copy its pages into a new document, and generate the merged file — all on your device. No file is sent to any server at any point. You don't have to take our word for it: open your browser's developer tools (F12), switch to the Network tab, and run a merge. You'll see no upload request for your PDF content.

When people use this

Students: combining assignment sections, scanned notes, or a thesis and its appendices into one submission.
Small business: assembling an invoice, quote, and terms into a single client-ready document.
Admin work: merging scanned forms, ID copies, or travel bookings into one file for email or upload elsewhere.

Good to know before you merge

Page order follows the order you select files in — reselect in the correct sequence if needed, since this version does not support drag-to-reorder yet.
Very large files (roughly 1GB+) depend on your device's available memory; older phones may struggle where a laptop won't.
Password-protected PDFs aren't supported yet — unlock the file first, then merge.
Output quality is unchanged: pages are copied, not recompressed or re-rendered.

Frequently asked questions

Is merging PDFs with PDFTeq really free?

Yes — no sign-up, no watermark, no file-count limit.

Are my files uploaded to a server?

No. Everything runs client-side via pdf-lib. See "How PDF merging works" above for how to verify this yourself.

Is there a file size limit?

No limit set by us — the ceiling is your device's available memory.

Can I merge password-protected PDFs?

Not currently. Remove the password first, then merge the unlocked file.

Will merging reduce quality?

No — pages are copied as-is.

Does this work offline?

The page and script need to load once over the internet; the merge itself then runs without a network connection.