Merge PDF
Combine multiple PDFs into one. Reorder by dragging. Runs in your browser — files never leave your device.
How it works
Drop two or more PDFs at once, or click to pick them. Each file appears in a list with its size, and you drag the rows to set the order the documents will be stitched in. Press Merge and the combined file downloads as merged.pdf. Pages keep their original order inside each document; only the documents move relative to each other.
What it accepts
Any number of .pdf files, in one go. Non-PDF files in the drop are ignored rather than aborting the batch, and fewer than two PDFs gets you a message instead of a pointless one-file merge. Encrypted or password-protected documents stop with an explicit error — pdf-lib will not open them, and guessing at passwords is not something a page like this should do.
Limits
The document outline — the bookmark tree in the sidebar — is not carried across, and interactive form fields often stop working once pages are pulled into a new document. Page content, images and text stay intact. Very large batches are bounded by memory: every file is held open at once, so a dozen small reports merge instantly while a few hundred-megabyte scans may not.
Why it runs in your browser
Merging is just copying page objects from one document into another, which pdf-lib does in JavaScript on your own machine. There is no upload step, so there is no waiting on a queue and no copy sitting in someone else’s storage afterwards. That matters most for the everyday case: signed contracts, invoices and scanned paperwork that you are combining precisely because they are yours.