Merge PDF

Combine multiple PDFs into a single document.

Runs entirely in your browser. Your data is never uploaded.

About Merge PDF

Merge PDF joins several PDFs into one file in the order you choose. Everything runs locally with pdf-lib — your documents never leave your device.

Merge PDF is one of dozens of free pdf tools on Crystal Toolkit. When you open this page, the tool loads in your browser and is ready to use immediately — there is nothing to install and no account to create. Everything you enter is handled locally using fast, modern web technology, so the work happens on your device rather than on a remote server. This approach keeps your information private, removes upload and download waiting time, and lets the tool keep working even on a slow connection once the page has loaded.

How to use Merge PDF

1Add the PDFs to merge.
2Drag to reorder them.
3Download the merged PDF.

Key features

Edits PDFs locally with the open-source pdf-lib engine
Keeps confidential documents on your device — never uploaded
Handles multi-page documents quickly
100% free with no sign-up, account or watermark
Mobile-first design that works on any device

Common use cases

Combining and organising documents before sharing
Preparing assignments, reports and contracts
Fixing page order and orientation without a desktop app

Why use Crystal Toolkit?

Unlike many online pdf tools, Crystal Toolkit runs Merge PDF entirely inside your browser. That means your data is processed on your own device and is never uploaded to a server, so it stays private and the results appear instantly. There is no sign-up, no daily limit and no watermark — just a fast, focused merge pdf you can use as often as you like, on desktop or mobile. Crystal Toolkit is built and maintained by CrystalSoftonic and is funded by unobtrusive ads, which is how we keep every tool completely free.