PDF Merger
Drop in your PDFs, drag them into the right order, and download one combined file. The merging happens on your device — nothing is uploaded.
Drop PDF files here or click to choose
Add as many as you like · nothing is uploaded
How merging works, and where your files go
Merging copies every page from each document into a new PDF, preserving the original page content exactly. Text stays selectable, links keep working, and quality is unchanged because nothing is re-rendered. This tool does that work in your browser: the PDF engine is a JavaScript library loaded from a CDN, but your actual files are read locally and never transmitted. Most free PDF sites upload your document to their servers instead — which matters when the document is a contract, a bank statement or a medical letter.
What "runs in your browser" means here
Worth being precise, because this tool works slightly differently from the others on the site.
Parsing an arbitrary PDF is genuinely hard — cross-reference tables, object streams, several compression formats and decades of edge cases. Rather than reimplement that, this page loads pdf-lib, an open-source library, from a public CDN.
That means one request to cdnjs.cloudflare.com for the library code. Your PDFs are not part of that request. They are read from your disk by your browser, merged in memory, and written back out as a download. No file content leaves your device at any point, which you can confirm in your browser's network tab.
What it can and cannot do
| Handled | |
|---|---|
| Text, images and vector graphics | Yes, copied exactly |
| Mixed page sizes and orientations | Yes, each page keeps its own |
| Links within a page | Yes |
| Bookmarks and outlines | No — these are dropped |
| Form fields | Usually flattened or lost |
| Digital signatures | Invalidated, as with any editing |
| Password-protected files | No — remove the password first |
Digital signatures are worth understanding: a signature certifies a specific document, so any modification, including merging, necessarily breaks it. That is the signature working correctly rather than a bug.
How to use the PDF Merger
- Drop in the PDFs you want to combine, or click to choose them.
- Drag the rows to put them in the right order.
- Press Merge into one PDF and the combined file downloads.
Frequently asked questions
Are my PDFs uploaded?
No. Only the library code is fetched from a CDN. Your files are read locally, merged in memory and downloaded — no file content is transmitted.
Is there a file size or page limit?
No fixed limit, but everything is held in memory, so very large documents can slow the browser. Several hundred pages is comfortable on a typical machine.
Can I merge password-protected PDFs?
No. Encrypted files must have the password removed first, usually in the program that created them or in Acrobat.
Does merging reduce quality?
No. Pages are copied rather than re-rendered, so text remains selectable and images are unchanged. File size is roughly the sum of the inputs.
How do I reorder the files?
Drag any row up or down. The number on the right shows where that file will land in the output.
Why did my form fields disappear?
Interactive form fields belong to their original document’s structure and generally do not survive a merge. Flatten the form first if you need the filled-in values preserved as visible text.
Related tools
Last reviewed September 4, 2026. Results are estimates for general information only.