Merge PDF Files

Combine PDF Files Without Uploading Them

When you merge PDFs with PDFb2, every file stays on your device. The merging algorithm runs entirely in your browser using JavaScript — your documents are never sent to a server, stored in cloud infrastructure, or accessible to anyone other than you. This is the fundamental difference between PDFb2 and cloud-based alternatives that require uploading your files.

Merging works by reading each PDF into browser memory, copying pages sequentially into a new document, and saving the combined result directly to your device. You can add up to 30,000 files, reorder them by dragging, and preview page counts before merging. Password-protected PDFs are supported — you enter the password locally and the decryption happens in the browser.

Common Uses for PDF Merging

Accountants combine invoices, receipts, and statements into single files for client delivery. Lawyers merge exhibits, contracts, and correspondence into filing bundles. Students assemble lecture notes, handouts, and assignments into study packets. Real estate agents compile inspection reports, disclosures, and contracts into transaction packages. In each case, the documents often contain private information that should not pass through third-party servers.

How It Handles Large and Protected Files

PDFb2 processes files of any size, though very large merges (200MB+) may take longer on devices with limited memory. If a file is password-protected, you will be prompted to enter the password before it can be included. Files with DRM protection cannot be merged in the browser — this is a security measure built into the PDF specification. For restricted PDFs (owner password), you can choose to proceed or skip the file. The progress bar shows real-time status as each file is loaded and merged, so you always know where the process stands.