Merge PDF Files Online - Secure & Instant

Drop your PDF files, drag to reorder, and click merge. The combined PDF downloads instantly — everything runs in your browser, no server upload.

You'll need to unlock them first using MiOffice's Unlock PDF tool. Once unlocked, drop them into the merger like any other file.

Up to 20 files with a combined size of 100MB. No daily limits, no account required.

Never. No watermarks, no branding, no quality reduction. The output is identical to what you'd get from Adobe Acrobat.

Yes. Works on iPhones, iPads, Android phones, and tablets — any device with a modern browser. No app to install.

Yes. Drag and drop the files to set the exact order. The merged PDF follows your arrangement.

Your PDFs never leave your device. MiOffice uses WebAssembly to process everything locally in your browser — no server, no cloud, no third parties.

Same merge quality, but MiOffice is completely free, requires no account, and processes files locally instead of uploading them to a server.

After the first page load (which caches the WASM engine), you can merge PDFs offline. Great for air-gapped or low-connectivity environments.

Use MiOffice's Compress PDF tool right after merging. It can shrink image-heavy PDFs by 50-90% while keeping text sharp.