Merge PDF

Merging needs at least two files and no account.

1. Drop your PDFs on the upload area, or click it and choose several. Each file is listed with its name and size. Files that are not PDFs are skipped with a message.
2. Put the list in the order you want the pages to appear, using the up and down arrow buttons beside each file. The file at the top supplies the first pages. The cross button removes a file you added by mistake.
3. Click Merge PDF. The pages are copied into a new document on your device.
4. Read the result card, which gives the number of files, the total pages and the size, then click Download to save merged.pdf.

The merge itself is quick. Ordinary office files take well under a second, and the page count on the result card lets you confirm that nothing went missing. Adding the same file twice repeats its pages, which is handy for a form you want in several places. A password-protected file stops the merge with a message naming it. Remove the password in your PDF reader, then add the unlocked copy. Clear empties the list.

The tool uses pdf-lib, an open-source JavaScript library that reads and writes PDF files without a server. It opens each file, creates a new empty document and copies every page across in list order. Pages carry their fonts, images and vector drawings with them, so nothing is rendered to a picture or recompressed. Text stays selectable and searchable, page sizes and orientations are kept, and the output is roughly the sum of the inputs.

Here is a worked example. A cover letter of 1 page, a CV of 2 pages and a certificates file of 3 pages are listed in that order. The result has 6 pages: page 1 is the letter, pages 2 and 3 the CV, and pages 4 to 6 the certificates. If the certificates should come before the CV, move that file up one place and merge again; nothing else needs redoing.

The merger copies pages and does nothing else. It does not rebuild bookmarks, join form data from different files or combine document properties, and the result is a new document, so the title and author of the sources are not carried over. Check any interactive PDF in your viewer after merging. If a form matters, print each source to PDF first so it becomes plain pages. Page numbers printed on the original pages are part of the page content, so they stay as they were and will not renumber across the combined file.

Merging does not compress. If the result is too big to email, with many mail services capping attachments at roughly 20 to 25 MB, the cause is usually large scanned images inside the sources. Pick pages before merging with the split PDF tool, and fix sideways scans with rotate PDF. If your pages are photographs, the image to PDF converter builds a PDF from them, and the image compressor can shrink the pictures first.

The list reorders whole files only. You cannot interleave pages from two files without splitting them first, and there is no drag-and-drop reordering, only the arrows. There is no preview of the pages, so open the result in a viewer to check the order. A few typical jobs are joining a cover letter with a CV, assembling invoices and receipts for an expense claim, and stitching scanned chapters into one document. Everything happens in the browser tab, which means the practical limit is memory: hundreds of pages of text merge at once, while gigabytes of high-resolution scans may be slow or fail on a phone. To turn pages into pictures instead, use the PDF to JPG converter.