Merge PDF Files

When merging PDFs saves you time

Most people reach for a merge tool when a website, a teacher or an office asks for "one file". A job application wants your CV, cover letter and certificates as a single PDF. An accountant wants every invoice for the quarter in one document. A visa portal accepts only one upload per section. Merging also helps when a scanner produced one PDF per page, or when you want to keep a contract and all of its signed annexes together so nothing goes missing.

How page ordering works

As soon as you add files, every page of every PDF appears as its own thumbnail card. The pages are flattened into one list, in the order the files were added, so you are not limited to placing whole documents before or after each other. You can:

• Drag any page by its handle to a new position, even between pages of a different file.
• Delete single pages you don't need, such as blank backs of scanned sheets or an old cover page.
• Add more files at any time with the "Add More" button; their pages are appended to the end of the list.

The counter at the top shows how many files and pages are currently in the list, which is a quick way to confirm nothing was skipped before you download.

What is kept in the merged file

Pages are copied into the new document as they are. Text stays selectable and searchable, images keep their original resolution, and each page keeps its own size and orientation. That means you can safely combine an A4 letter with a US Letter form or a landscape spreadsheet; every page will look exactly as it did in its source file. Nothing is re-rendered or re-compressed, so merging never lowers quality.

Two things belong to the old documents rather than to their pages and are not carried over: the bookmarks panel (the document outline) and interactive form behaviour. If a file contains fillable fields, fill them in and save a flattened copy first (for example with "Print to PDF" in your PDF reader), then merge that copy.

Tips for a clean result

• Name files before you start. Pages are added in the order you select files, so numbering them (01-cv.pdf, 02-letter.pdf) gives you the right order immediately.
• Check the first and last pages. Reviewers usually look at the first page only. Put the most important document first.
• Choose a clear output name. Use the "Output File Name" field to give the file a descriptive name such as "Jane-Doe-application-2026" instead of "merged-document".
• Watch the upload limit of the destination. If the merged file is too large for a portal, see our guide on making a PDF small enough to email.

Password-protected PDFs

A PDF that needs a password to open cannot be read by any tool until it is unlocked. Open it in your PDF reader with the password, save or print an unprotected copy, and add that copy here. Files that only restrict printing or editing usually open normally.

Your files stay on your device

The merge runs entirely in your browser using the open-source pdf-lib library. Your PDFs are read from your disk into the page's memory, assembled there, and the result is handed straight back to you as a download. Nothing is uploaded, so the tool also works for confidential documents such as contracts, medical records or bank statements. Very large documents are limited only by the memory of your device; on a phone, merging a few hundred pages at a time is comfortable, and a desktop browser can handle considerably more.