Merge PDF Files
Combine multiple PDF files into one document, right in your browser.
About the Merge PDF
The Merge PDF tool combines several PDF files into a single, tidy document — in the order you choose — without ever uploading anything. Pick two or more PDFs, drag them into the exact sequence you want, and download one merged file. Everything runs inside your browser using JavaScript, so your documents never leave your device: nothing is sent to a server, nothing is stored, and nothing is logged. Close the tab and every trace is gone.
Merging PDFs is one of those small chores that comes up constantly. You might need to staple a cover letter to a résumé, bundle scanned receipts into one expense report, join the chapters of an e-book, combine signed contract pages, or assemble a handful of invoices before emailing them to a client. Doing it online usually means trusting a website with private paperwork. This tool avoids that entirely by keeping the whole process local, which is faster too — there's no upload wait and no file-size ceiling imposed by a server.
How to use
- Add your PDFs. Drag and drop your files onto the drop zone, or click it to browse and select them. You can add more files at any time, and only files ending in
.pdfare accepted. - Put them in order. The list shows your files top to bottom, which is exactly the page order of the final document. Use the up and down arrows to rearrange, and the X to remove any file you added by mistake.
- Merge and download. Click Merge & Download. The tool reads each PDF, copies every page into a fresh document in your chosen order, and immediately downloads the result as
merged.pdf. - Start over anytime. Click Clear all to empty the list and begin a new merge. Since nothing was uploaded, there's nothing to clean up on any server.
Frequently asked questions
Are my PDF files uploaded to a server?
No. The merge happens locally in your browser using the pdf-lib library loaded with this page. Your files are read straight from your device into memory, combined, and handed back to you as a download. They are never transmitted over the network, saved, or seen by anyone but you.
How many PDFs can I merge at once?
There's no fixed limit. You need at least two files to merge, and from there you can add as many as you like. Because the work runs on your own computer, the practical ceiling is your device's available memory. Very large files or dozens of documents may take a few seconds and briefly use more memory while combining.
Can I control the order of the files?
Yes. Each file appears in a numbered list, and that order becomes the page order of the merged PDF. Use the up and down arrows next to any file to move it, and the remove button to drop it. Rearranging is instant and doesn't re-read the files.
Will merging change the quality of my pages?
No. Pages are copied intact from each source PDF into the new document, so text stays selectable, images keep their resolution, and layouts are preserved. The tool doesn't re-compress, re-render, or downscale anything — it simply places the original pages one after another.
What happens with password-protected or encrypted PDFs?
Encrypted or password-protected files usually can't be opened for merging, and corrupted files may fail to load. If the tool can't read a file, it stops and tells you which one caused the problem so you can remove it or provide an unprotected copy. Please unlock any protected PDFs before merging them.
Does this work offline?
Once the page has loaded in your browser, the merging itself needs no internet connection because all the processing is done on your device. If your browser has already cached the tool, you can even open it and merge files while offline. Either way, no connection is used to handle your documents.
Which browsers and devices are supported?
Any modern browser works — Chrome, Firefox, Safari, and Edge on desktop, plus mobile browsers on phones and tablets. There's nothing to install and no account to create. On lower-memory devices, merging a very large batch of big PDFs may be slower, but small everyday merges are quick everywhere.