How to merge PDFs
- 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.
- Check the numbers. The merged document follows the list from row 1 downward. If a file is in the wrong place, click Remove on it and add it again, or click Clear all and add the files in the order you want.
- Look at the total in the summary line (for example, 3 files, 41 pages total) and make sure it matches what you expect.
- Click Merge PDF. A single file named
merged.pdfis 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
The tool does not have drag handles, so the order is decided when you add the files. 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. 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. 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 asmerged (1).pdfand 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.
Frequently asked questions
Does the order matter?
Yes. Files are merged top to bottom in the order shown in the list, and every page of a file stays together in its original sequence. To change the order, remove the misplaced file and add it again, or clear the list and add the files in the order you want.
Can it merge password-protected PDFs?
No. A file that is encrypted cannot be read, so it is flagged as unreadable and left out of the merged result. Remove the password in the original program or re-save the document as a new PDF, then add it again.
Are my PDFs uploaded?
No. Everything runs in your browser on your own device and nothing is sent to a server. The merge still works if you disconnect from the internet after the page has loaded.
Will the merged PDF be smaller or lower quality?
No quality is lost because pages are copied rather than re-rendered, so text stays sharp and searchable. The file size is usually about the sum of the input sizes. This tool does not compress, so a large result needs a separate compression step.
Can I merge PDFs with different page sizes?
Yes. Each page keeps its own size and orientation, so you can mix A4, Letter and landscape pages. Some printers scale them differently, so rotate or fix problem files first if the output has to look uniform.
Is there a limit on how many files or pages I can merge?
There is no fixed limit in the tool. The practical limit is your device's memory, because every file is loaded into the browser. If a very large merge fails, combine the files in smaller batches and then merge the results.
Do bookmarks and form fields survive the merge?
Not reliably. The pages and their visible content are copied, but document-level features such as bookmarks or interactive form fields may not be carried over. Print a filled form to PDF first if its values must appear in the merged file.
Is it free?
Yes. It is completely free, with no watermark, no sign-up and no daily limit.