How to Merge PDF Files Into One Document

Merging PDFs is one of the most common document tasks. Job applications often ask for a single file containing a CV, cover letter and certificates; accountants want all invoices for a month in one document; and teachers combine worksheets into one handout.

How to merge PDF files online

1. Open the PDF Merger.
2. Add two or more PDF files — click to select them or drag them onto the upload area.
3. Arrange the files in the order you want. The first file in the list becomes the first pages of the merged PDF.
4. Click merge and wait while the PDFs are combined in your browser.
5. Download the merged PDF and open it to check the page order.

Before you merge: a quick checklist

• Name files clearly (for example 01-cover.pdf, 02-report.pdf) so ordering is easy.
• Remove unwanted pages first using Remove PDF Pages.
• Fix orientation of sideways scans with the PDF Rotator.
• Check size limits — if the merged file is too large, run it through the PDF Compressor.

Merging images and PDFs together

If some of your pages are photos or scans saved as JPG or PNG, convert them first with Image to PDF, then merge the resulting PDF with your other documents.

Common problems and fixes

• Encrypted PDFs: files protected with an owner password may refuse to merge. Open them with the password in a PDF reader and save an unprotected copy first.
• Different page sizes: A4 and Letter pages can be merged; each page keeps its own size.
• Form fields: interactive form fields may be flattened or behave differently after merging. Fill forms before merging when possible.

Always keep your original files until you have checked the merged document.