How to merge PDF files into one, in the right order

Putting several PDFs into one is a daily job: a form plus its supporting documents, scanned pages from a phone, or a report that was exported in parts. Done right, the merged file keeps selectable text, working links and sharp images. This guide covers the steps and the problems people hit.

How to merge PDFs

1. Open PDF Merger and add all the files at once. You can also drag them onto the page.
2. Drag the file cards into the order you want. The first card becomes the first pages of the result.
3. Click Merge and download the single PDF.

Fix the order after merging

If one page ended up in the wrong place, you do not need to merge again. Open the result in Organize PDF Pages, drag pages into position, rotate any that are sideways and delete blanks. Then save the new file.

Keep the size down

A merged PDF is about the sum of its parts. If an upload form has a limit, such as 1 MB or 2 MB, run the result through Compress PDF. For scans the “Pages to images” option gives the smallest file; see how to compress a PDF under 100 KB.

Common problems

• A file asks for a password. Enter it once when asked. The merged file opens without that password. To protect the final file, use Protect PDF.
• Pages have different sizes. Merging keeps each page’s own size, so an A4 page can sit beside a phone-screenshot page. Convert images with Image to PDF using A4 pages first if you want them uniform.
• The order looks wrong. File names like page10.pdf sort before page2.pdf. Number them 01, 02 or just reorder by dragging.
• Page numbers are missing or repeat. Add them after merging with Add Page Numbers so the numbering runs across the whole document.

Frequently asked questions

Does merging reduce quality?

No. Pages are copied as they are, without being re-rendered or recompressed.

Is there a limit on the number of files?

Only your device’s memory. Dozens of normal documents are fine; very large scans may be slow on an older phone.

Is it safe to merge confidential documents?

Merging happens in your browser and the files are never sent to a server, so it is as private as working offline.