Merge PDF

This tool uses pdf-lib, an open-source JavaScript library that reads and writes PDF files entirely in the browser. When you add PDF files, they are loaded into your browser's memory as binary data. The merge process copies every page from each document into a new, combined PDF in the order you specify. The final file is generated locally and downloaded directly to your device. No server is involved at any point, which means your documents stay completely private.

Combining PDFs is useful in many everyday situations. You might need to merge multiple scanned pages into a single document for an application or submission. Freelancers often combine a cover letter, resume, and portfolio into one file. Students merge assignment pages, reference materials, or research papers. Businesses consolidate monthly reports, contracts with attachments, or multi-part proposals into a single deliverable that is easier to share and archive.

Arrange your files in the correct order before merging by using the drag handles or arrow buttons. If a PDF fails to merge, it may be password-protected or use a format variant that the browser library cannot parse. In that case, try opening the problematic file in a PDF reader and re-saving it as a standard PDF first. For very large merges, close other browser tabs to free up memory. The merged file preserves the original page sizes, so documents with mixed page dimensions will merge without any cropping. If your merged document includes images that need optimization, try our Image Compressor to reduce their size before embedding. Our Invoice Generator can also create professional PDF invoices that you can merge with other documents.