Merge PDF files without uploading them
Combine multiple PDFs into one — in order, in seconds, offline.
Processed on your device — nothing is uploaded. Works offline.
How to merge PDF files without uploading them
- 1Drop two or more PDFs onto the page, or click to choose them.
- 2Put them in order: drag a file up or down the list, or use the arrows. The output follows the list from top to bottom.
- 3Click Merge. The combined file is assembled in your browser's memory.
- 4Download the merged PDF. Nothing was sent anywhere — you can do all of this with your wifi off.
Every step runs in this tab. The site has no upload endpoint, and the page's security policy forbids the browser from contacting any other server — see how that is enforced.
When you'd use it
Contract plus exhibits
A signed agreement with its schedules and annexes as one file for filing, without the whole deal passing through someone else's server.
Scanned paperwork
Invoices, receipts and forms scanned one page at a time, stitched into a single document.
Application packs
CV, cover letter and certificates as one PDF, in exactly the order the employer asked for.
Good to know
- The output follows the list order exactly, and each page keeps its own size, so mixed A4 and Letter files merge without cropping.
- A password-protected file won't merge until the password is removed — run it through Unlock PDF first.
- Batches are limited only by your device's memory; a few hundred megabytes is fine on a laptop.
Don't trust us — test us
“Your files never leave your device” is a claim every PDF site makes. Here it is checkable in under a minute, three different ways:
- Watch the network.Open your browser's developer tools, switch to the Network tab, then run the tool. The only requests you will see are the site's own files — none of them carries your document — and once the app is cached there are no requests at all.
- Pull the plug. Load this page, turn off your wifi or switch on airplane mode, then use the tool. It keeps working, because there is no server involved and nowhere to upload to.
- Read the headers. The response headers for this page include a Content-Security-Policy with
connect-src 'self': the browser itself refuses to send anything to another host, whatever the code asks.
The full privacy model, including what we can't protect you from →
Guide
How to merge PDFs without uploading them
Merging is the most common reason people upload confidential paperwork to a stranger's server. It doesn't need one. Step by step, with the checks that prove it.
Frequently asked questions
How do I change the order of the merged files?
Drag files up or down in the list before merging, or use the arrow buttons. The output follows the list order exactly.
Can I merge PDFs with different page sizes?
Yes. Every page keeps its original dimensions, so an A4 report and a Letter-sized scan sit side by side in the output without scaling or cropping.
Are my files uploaded to a server?
No. All processing happens inside your browser using WebAssembly and JavaScript. Our server only serves the app itself — there is no endpoint that can receive files. You can verify this in your browser's network tab, or turn off your wifi after the page loads: everything still works.
Does it work offline?
Yes. After your first visit the whole app is cached by a service worker, so the page loads and every tool works with no connection at all. Load the page, switch on airplane mode, and carry on.
Is there a file size limit?
No hard limit — your device's memory is the ceiling. Files up to a few hundred MB work well on a typical laptop. Very large files may be slow or fail on low-memory devices; nothing is ever truncated silently.
Do I need to create an account?
No. No account, no email, no cookies. The free tools are simply free.
Which browsers work?
Current Chrome, Edge, Firefox and Safari, on desktop and on phones. Phones have less memory, so very large files are better handled on a laptop.