How-to guide

How to merge PDF files

Combine multiple PDFs into a single file — in any order, without creating an account or uploading anything to a server.

Every file you drop stays in your browser — nothing is transmitted when combining.

Merge PDF — files stay local How local processing works →

Why local merging matters

When you merge PDFs using an upload-based tool, every file you combine is transmitted to a third-party server. If you are merging a contract with an appendix, or combining payroll documents from multiple months, all of that content transits their infrastructure simultaneously.

Filecraft's Merge PDF tool runs the combination entirely in your browser using WebAssembly. Your files are read into browser memory, merged there, and written back to your device. No copy exists on any server at any point.

Step by step

Five steps from separate files to a single merged PDF — all in your browser.

1
Open the Merge PDF tool
Navigate to the Merge PDF tool. No account is required to use it.
2
Drop your PDF files
Select or drag all the PDFs you want to combine. Each file is read into your browser's memory.
File location: Your browser
3
Reorder if needed
Drag the files into the order you want them to appear in the merged output.
File location: Your browser
4
Click Merge
The merge runs locally using WebAssembly. No network request is made for your files.
File location: Your browser
5
Download the merged PDF
The combined file is written directly to your device. Close the tab and browser memory is cleared.

Merge PDF — files stay local

Common questions

Does merging PDFs reduce quality?

No. The merge operation combines the page streams from each file without re-encoding content. Text, images, and vector graphics are preserved exactly as they appear in the originals.

Can I reorder pages before merging?

Yes. After dropping your files, you can drag to reorder them before clicking Merge. The output will reflect the order you set.

Is there a file count or size limit?

Free accounts can merge files up to the free plan file size limit. Pro accounts have a higher limit. There is no cap on the number of files you can merge in one session.

Does the merged file get uploaded anywhere?

No. All processing happens in your browser using WebAssembly. None of your files — the inputs or the merged result — are transmitted to any server. You can verify this by opening the Network tab in your browser developer tools while merging.

How local processing works →How to split a PDF →How to compress a PDF →Combining scanned documents →