How to Merge PDF Files for Free (Without Uploading Anything)
Updated August 1, 2026
Why merge PDFs in your browser?
Most online PDF mergers upload your files to a server. That means contracts, invoices or medical records pass through someone else's infrastructure. Browser-based merging is different: the files are read by your own device, combined locally, and never transmitted anywhere.
PDFImageTools uses the pdf-lib engine running in a sandboxed browser tab. You can even disconnect from the internet after the page loads and merging still works.
Step-by-step
Open the Merge PDF tool and drop in two or more PDF files.
The files are merged in the order they appear — add them in the sequence you want.
Click Merge PDF, wait a moment, and download the combined document.
Tips for large merges
Merging is memory-bound: very large documents (hundreds of pages each) work best on a desktop browser.
If the merged file is too large, run it through the Compress PDF tool afterwards — the Balanced level usually cuts scanned documents by 60-80%.
Ready to try it?