Merge PDF

Combine PDFs without sending them anywhere

Merging is the everyday PDF chore: a contract and its annexes, scanned receipts for an expense claim, the chapters of a thesis, several invoices for an accountant. Most online mergers upload every file to a server first. This one works on your own computer or phone: the files are read by your browser, combined there, and the merged PDF is saved straight to your device.

Add the files, use the arrows to put them in order and press Merge PDFs. The first file's pages come first, then the second file's, and so on. You can add more files after the first batch, remove one with the × button, and merge up to 100 files at once.

What is kept

Every page is copied as it is: text, fonts, images, page size and orientation, and links on the page. Bookmarks and form fields that belong to one of the source documents are not carried over, because each document's outline would clash with the others.

The files are opened in a Web Worker with pdf-lib, an open-source PDF library. Each page is copied into a new document together with the fonts and images it uses, so nothing is rasterised or re-encoded. The new document is written with compressed object streams and offered for download. Because nothing is uploaded, there is no account, daily limit or file-size cap beyond what your device's memory can hold.