Merge PDF

What this tool does

Merge PDF joins any number of PDF files into a single document. Drag the files into order, pick only the pages you need from each one, and download the combined PDF without uploading anything.

Application portals, accountants and print shops often want one file, not six. Scanned receipts, a signed contract and its appendices, or monthly statements tend to arrive as separate PDFs, and attaching them one by one is error-prone. Merging them into a single, correctly ordered document makes the bundle easier to send, review and archive.

This tool uses the pdf-lib library to copy pages from each source file into a new PDF. Pages are copied as they are, so text stays selectable, vector graphics stay sharp and images are not recompressed. The work happens in your browser tab, which means confidential files such as payslips or medical letters never leave your device.

How to use Merge PDF

1. Drop your PDF files onto the upload area or click to browse. You can add more files at any time.
2. Set the order by dragging the rows, using the up and down arrows, or pressing Sort by name.
3. Optionally type a page range next to a file, such as 1-3, 7, to include only those pages.
4. In Options, set the output file name and choose whether to insert blank pages for double-sided printing.
5. Press Merge PDFs and wait for the progress bar to finish.
6. Check the page count in the result, then press Download or Open to view the merged file.

Tips for better results

• Number your files before adding them (01-cover.pdf, 02-letter.pdf) and Sort by name will put them in order instantly, with 10 correctly placed after 9.
• Ranges accept open ends: 5- means page 5 to the last page, which is handy when you only want to drop a cover page.
• The blank-page option keeps every document starting on a right-hand page when the merged file is printed duplex.
• Very large merges (hundreds of pages of scans) can use a lot of memory; if the tab slows down, merge in two halves and then merge the results.

Common use cases

• Combining a CV, cover letter and certificates into one application PDF.
• Joining monthly bank statements into a single annual file for a tax return.
• Bundling an invoice with its delivery notes and receipts for an expense claim.
• Assembling chapters exported separately from a word processor into one book proof.

Common mistakes to avoid

• Adding password-protected PDFs: encrypted files cannot be rewritten, so remove the protection in the original app first.
• Forgetting that bookmarks (outlines) and fillable form fields from the source files are not carried over; the visible page content is.
• Typing page numbers from the printed page footer rather than the PDF page position; range numbers always count from the first page of the file.