How to merge PDF files into one on Windows
Short answer: in Contenta Converter, add the PDF files on the Files step in the order you want them, click Next: Operations, tick the Merge PDFs card, then click Start Converting. You get one file, merged.pdf, in the output folder, with every page of every file in list order. The text stays selectable because the pages are copied, not turned into pictures.
Scanners produce one PDF per pass. Accounting wants one PDF per month. Online merge tools take the upload, but a signed contract or a medical scan is not something to hand to a website. Contenta Converter merges on your own PC and the files never leave it.
Merge PDFs, step by step
- Open Contenta Converter. On the Files step, click Add Files or drag the PDFs onto the window. The order of the list is the order of the merged file: tick a file and use the up and down arrows in the list toolbar to move it.
- Click Next: Operations and tick the Merge PDFs card (“Append PDFs into one file”).
- If you only want the merged file, switch the Convert card off. Otherwise each PDF is also converted to the output format you choose, page by page, next to the merged file.
- Click Next: Configure and choose the output folder. The merged file is always called
merged.pdf; a file with that name in the output folder is replaced. - Click Start Converting. The result line reads “1 merged PDF”. Open the output folder and check the page count.
What the merged file looks like
| Question | What happens |
|---|---|
| Page order | The order of the file list on the Files step, then every page of each file in its own order. Move files up or down before you start; there is no page picker. |
| File name | Always merged.pdf in the output folder. Rename it in Explorer afterwards, or give it a name with the command line (below). |
| Text and links | Kept. Pages are imported as PDF objects, never rendered to an image, so search, copy and select still work. |
| Page size | Each page keeps its own size. An A4 scan and a Letter invoice stay A4 and Letter in the same file. |
| Photos in the batch | Ignored by the merge. Only files ending in .pdf go into merged.pdf; the photos go through the normal conversion. |
| A damaged or password-protected PDF | Skipped with an error line for that file. The merge carries on with the rest. |
| File or page limit | None. The merge is written to a temporary file first and moved into place when it is complete. |
Photos and scans that are not PDFs yet
JPEG or PNG scans do not go into the merge directly. Convert them first: add the images, choose PDF as the output format on the Configure step and click Start. Each image becomes a one-page PDF. Then merge those PDFs in a second run.
For a photo album with several photos per page, use the Create PDF Album card instead; the PDF photo album guide covers page sizes and photos per page.
From the command line
The same merge is one command with the Contenta CLI, and here you can name the output file:
contenta pdf-merge chapter-1.pdf chapter-2.pdf chapter-3.pdf -o book.pdf
Without -o the output is merged.pdf in the folder of the first file. The MCP server exposes the same operation as merge_pdfs for AI agents.
Merging PDFs: questions
Does merging change the quality of the pages?
No. The pages are copied as they are, including their fonts, vector drawings and embedded images. Nothing is re-compressed.
Can I pick only some pages of a file?
Not in the merge. Every page of every listed file goes in. To drop pages, convert that PDF to single-page PDFs first, remove the ones you do not want, and merge the rest.
Are my PDFs uploaded anywhere?
No. The merge runs on your Windows PC. Contenta Converter does not send files to a server.
What does the free trial do with a merge?
The trial has no time limit. A merged file made on the trial gets one extra page at the end reading “Made by contenta-converter.com”. A license removes it.
Merge your first PDFs
Download Contenta Converter and combine your scans on your own PC. Windows 10 and 11, 64-bit.
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