How to merge PDF files
- Drop your PDF files onto the box above, or press Browse files to select several at once.
- Check the order in the list. Use the up and down arrows to move a document, or the cross to remove one.
- Press Merge PDFs and wait for the progress bar to complete.
- Confirm the page count shown against the result matches what you expected.
- Download the combined document.
What this merger does
- Combines up to thirty documents of any length in a single operation.
- Lets you reorder files before merging rather than forcing you to add them in sequence.
- Copies pages at their original quality. Nothing is re-compressed or rasterised.
- Preserves each document's own page size, so mixed A4 and Letter files merge cleanly.
- Reports the total page count so you can verify nothing went missing.
- Runs entirely offline once loaded, with no file size cap beyond your device's memory.
Why one document beats five attachments
Anything that has to be read in order, filed, or signed benefits from being a single file. A loan application assembled from six separate scans is an invitation for one of them to go missing. A report split across an executive summary, three chapters and an appendix gets read out of sequence. Attaching five PDFs to an email also multiplies the chance of hitting an attachment limit.
Merging solves all of that in one step, and it is one of the few PDF operations that is genuinely lossless. The pages are copied across exactly as they were, with their fonts, images and vector artwork intact.
Where this comes up most
- Assembling scanned pages into one document after a scanner produced a file per page.
- Combining an invoice, a receipt and a delivery note into a single expense claim.
- Joining chapters, a cover page and appendices into a finished report.
- Putting a passport scan, proof of address and application form into one submission.
- Merging monthly statements into one file for an accountant or a tax return.
Order is the part people get wrong
Files are merged from the top of the list downwards, and the order your browser reports when you select several at once is not always alphabetical. It is worth glancing at the list before pressing the button, because fixing the order afterwards means starting again.
The arrow buttons move a document up or down one position, and the cross removes it. If a document only needs some of its pages, extract them first with the page extractor and merge the result. That is cleaner than merging everything and then deleting pages afterwards.
Mixed page sizes are fine
A PDF stores the dimensions of every page individually, so a merged document can contain A4 pages, Letter pages and a landscape spreadsheet without anything being scaled or cropped. Each page keeps exactly the size it had.
That is usually what you want. If you would rather everything matched, the practical route is to standardise before merging, for images, the JPG to PDF tool lets you pick one paper size for the whole batch.
What does not survive the merge
Page content is copied faithfully, but a few document-level features are not. Bookmarks and the table of contents belong to the original document rather than to its pages, so they are not carried over. The same applies to file attachments, and to form fields, which lose their interactivity because two merged documents would otherwise contain fields with clashing names.
If a source file is password protected, it has to be opened first, the PDF unlock tool handles that when you know the password. And because merging adds every page from every file, the result can be large; the PDF compressor will bring a scan-heavy merge back down.
Everything happens in your browser. Contracts, medical records and financial statements are exactly the documents people merge, and none of them are uploaded anywhere.