The Privacy of Client-Side PDF Merging

If you've ever needed to combine two PDF documents, you've likely Googled "merge pdf" and clicked on one of the top results. These services work great, but they all share one massive security flaw: they require you to upload your files to their servers.

The Risk of Remote Servers

When you upload a document to a free online service, you are trusting an unknown entity with your data. If you are merging sensitive financial records, private medical documents, or confidential legal contracts, uploading them to a random server is a massive security risk. Even if the service claims they delete the files after 24 hours, data breaches happen constantly.

How Client-Side Merging Works

Our tool flips the script by utilizing modern JavaScript and WebAssembly via a library called pdf-lib. Instead of sending your files to a server to be processed, we send the processing software to you. When you drag and drop your PDFs into our tool, they are read directly into your browser's local memory (RAM).

The code then extracts the pages from each PDF and stitches them together locally. Once the merge is complete, your browser generates a "Blob URL" (a temporary, local link to the data in your RAM) and downloads it directly to your hard drive. At no point does a single byte of your data travel across the internet.