Merge PDF

How to merge PDFs

1. Drop your PDF files onto the box, or click it and select several files at once. Each file appears as a numbered row showing its name and page count.
2. Check the numbers. The merged document follows the list from row 1 downward. If a file is in the wrong place, click its Up or Down button to move it one row at a time, or drag the row and drop it where you want it (a blue line shows where it will land). Remove deletes a file from the list, and Clear all empties it.
3. Look at the total in the summary line (for example, 3 files, 41 pages total) and make sure it matches what you expect.
4. Click Merge PDF. A single file named merged.pdf is downloaded to your device.

When merging PDFs is the right move

Most people merge PDFs because somebody on the other end wants one file. A loan or visa application might ask for a passport scan, three payslips and six months of bank statements as a single attachment. An accountant may want every receipt for a quarter in one document. A teacher might combine a worksheet and its answer key, and a freelancer might send a proposal, a contract and an invoice together so nothing gets lost in a long email thread. One file is also easier to print, to stamp with page numbers, and to archive under a single name.

Getting the order right

You can rearrange the list at any time before you merge. Click Up or Down on a row (the buttons work with the keyboard and on touch screens), or drag a row with the mouse and drop it above or below another row; a blue line marks the spot. The merged document always follows the list exactly as it is shown. Two habits save time. First, name your files with a numeric prefix such as 01-cover.pdf, 02-contract.pdf, 03-invoice.pdf. The order in which a file picker hands over a multi-file selection can differ between operating systems and browsers, so always confirm against the numbers in the list and fix any row that is out of place. Second, if you add files in several batches, each batch is appended to the end of the list, which is a handy way to build the document in stages; you can then move the new files to where they belong. The same file added twice is kept twice, so a duplicate row means a duplicate section in the output.

What happens to your pages

The tool copies the pages of each source file into a new document without re-rendering them. Text stays selectable and searchable, vector graphics stay sharp, and scanned pages keep their original image quality. Because nothing is recompressed, the output is typically close to the combined size of the inputs, so merging ten 2 MB files gives a file of roughly 20 MB. If that is too big for email, see our guide on why a PDF is too big to email.

Pages keep their own size and orientation, which means a merged file can contain A4 portrait, US Letter and landscape pages side by side. That is valid, but some viewers and printers handle it awkwardly. If one document came out sideways, fix it with the Rotate PDF tool and then merge. Only the pages themselves are carried over; features that belong to the whole document, such as bookmarks or interactive form fields, may not survive the merge. If you need a form’s filled-in values to appear, print the filled form to PDF first and merge that version.

Common problems and how to avoid them

• Password-protected files. A file that cannot be opened is listed with the note “Could not read (maybe encrypted)” and is left out of the result. Remove the password in the program that created it, or re-save it with “Print to PDF”, then add it again. Always compare the page total with what you expected, because a skipped file will not stop the merge.
• Very large inputs. Every file is read into your browser’s memory, and the finished document is built there too. Dozens of megabytes are fine on any modern computer; several hundred megabytes may fail on an older phone or tablet. If that happens, merge in two or three batches and then merge the results.
• Generic file name. The download is always called merged.pdf. Rename it straight away, or the next merge will end up as merged (1).pdf and it becomes hard to tell versions apart.
• Pages in the wrong spot after the merge. If you only need to drop or pick a few pages, use Delete PDF Pages or Extract PDF Pages on the result instead of starting over.

Is it private and safe?

Yes. The merge runs in your browser using a small open-source PDF library that ships with this site. Your files are never uploaded, which matters for contracts, medical letters, tax records and anything with ID numbers. There is no upload queue, no account to create and no watermark added to the result. The trade-off is that you are limited by your own device’s memory, and the tool does no editing beyond combining whole files.

Related guides

Step-by-step walkthroughs: How to merge PDF files, combining PDFs on Windows, merging PDFs on Mac and adding page numbers to the finished file.