Merge PDFs

Combine several PDFs into one file

A cover letter, CV and supporting documents for a job application or an official application often need to arrive as a single attachment. For this, the tool places whole PDF files one after another. The pages of the top file in the list come first, and the pages of the bottom file come last.

1. Click “Choose PDF files” and select at least two PDFs. If you missed a file, add it with “Add files”.
2. Check the file list. Use ↑ and ↓ next to the file name to move a file up or down, and × to remove it again. Before you start, the preview shows the file that is currently at the top. This lets you quickly see whether the right document is at the beginning.
3. Click “Merge PDFs”.
4. Scroll through all pages in the result preview. The page count should equal the sum of your source files, and each document should begin in the intended place.
5. Download the new PDF. Its name is based on the first file in the list. For example, Antrag.pdf becomes Antrag-zusammengefuegt.pdf.

If you change anything in the list after merging, that is, move, remove or add a file, the tool discards the previous result. This prevents you from accidentally downloading a version that no longer matches your selection. Then simply click “Merge PDFs” again.

Example for checking: You combine A.pdf with 3 pages and B.pdf with 2 pages, and A.pdf is at the top. The result preview must then show 3 + 2 = 5 pages. The saved file is named A-zusammengefuegt.pdf. If a document is missing or the file starts with the wrong page, check the selection and the order in the list.

The selected files are processed in your browser’s memory and are not uploaded to a server for this. JavaScript must be enabled. The result is always a new file. Your originals are neither overwritten nor changed.

Set the order before merging

The arrows always move whole files. Within each file, the page order stays as it is in the original. That is why you can predict what the result will look like before you click: the first page is the first page of the top file, and the last page is the last page of the bottom file.

Here, A1 stands for page 1 of A.pdf. Both variants have 5 pages. The only thing that changes is which document comes first.

You cannot alternate individual pages from different files or rearrange them by dragging here. If you need a mixed sequence, split the file in question beforehand. With the splitting tool, you can extract specific pages beforehand, save the new files and then select them here together with the other PDFs.

Example: You want the sequence A1, A2, B1, B2, A3. To do this, you create one file from A.pdf with pages 1 to 2 and a second file with page 3. In the list, you then arrange them like this: first pages 1 to 2 from A, then B.pdf, then page 3 from A. The result again has 5 pages.

Page sizes are not standardized. A landscape table stays landscape, and a smaller page stays small, even if all other pages are A4 portrait. There is no automatic conversion to a uniform paper size. If your recipient expects a particular format throughout, look out specifically for such pages in the result preview before you send the file.

Save images as PDF first

The tool only accepts PDF files. You cannot select JPG, PNG or Word files here directly. So convert photos and scanned images in a separate step, then add the finished PDF.

Example: Your application is available as a PDF, but one supporting document exists only as a phone photo in JPG format.

1. Open the page for converting JPG and PNG to PDF, create a PDF from the photo there and download it.
2. Come back here and select the saved PDF together with your application. The file is not automatically passed from one page to the other.
3. Put both files in the order you want and merge them.

This tool does not accept Word or Excel files. You can convert a simple DOCX file with only one section and at most 20 MiB beforehand using Word to PDF; in the process, the text is reflowed and the font is replaced. If you need the exact layout or have an Excel file, save or export it as a PDF in your office program. Then select the saved PDF here.

Distinguishing page content from document features

When merging, the existing pages are copied into a new PDF. They are not converted into images, and any photos they contain are not recompressed. So merging itself does not make your pages blurrier, and selectable text stays selectable. But no new text is created either: a scanned page without a text layer remains an image, because no text recognition takes place.

It is different for everything that belongs to the document as a whole and is not visible on a page. This includes bookmarks, metadata such as title or author, comments and annotations, and the behavior of links. Because the pages are transferred into a newly built file, there is no guarantee that these parts arrive complete and working. The same applies to standards such as PDF/A or PDF/UA. Even if your source files meet them, this is not guaranteed for the result.

After merging, the tool checks whether the new file can be opened and whether its page count is correct. This check cannot tell whether all document features still work.

Example: One of your documents contains comments and a clickable table of contents. The file is accepted, but after merging you see a notice. You check the visible content in the result preview. Whether the links and comments still work, you check in your PDF program before sending. If these features are important, it is better to send the document as a separate attachment.

Limits and unsupported documents

Merging is subject to limits per file and for all files combined. The page limit is especially important: 250 pages is the maximum for the entire result, not for each individual file.

Example: Three PDFs with 120, 90 and 60 pages have 270 pages combined. That puts them over the limit, even though each individual file stays well below it. Size works the same way: two files of 45 MiB each fit together, because that makes 90 MiB. If a third file of 15 MiB is added, that makes 105 MiB, which is too much.

The values are given in MiB. 1 MiB is 1,048,576 bytes. 50 MiB therefore corresponds to about 52.4 MB and 100 MiB to about 104.9 MB when calculated in decimal megabytes. Even below these limits, the process can abort if your browser or device runs out of memory. In that case, combine fewer files at once.

Ordinary, readable PDFs of versions 1.0 to 1.7 as well as 2.0 are accepted. The tool rejects these files:

• digitally signed or certified PDFs. A scanned signature or one inserted as an image is not a digital signature; such files can be combined normally.
• encrypted or password-protected PDFs
• PDFs with interactive form fields, including XFA forms and empty signature fields
• PDF portfolios and PDFs with embedded file attachments
• PDFs with layers that can be shown and hidden
• damaged, empty or incomplete files

What you do next depends on the reason. You can send an intact signed, encrypted or otherwise special PDF from this list unchanged as a separate file if your recipient accepts multiple files. Whether they accept it in this form is their decision. If in doubt, ask briefly. For a damaged, empty or incomplete file, however, an additional attachment won’t help. Export it again from the program it was created in, or get a complete, readable copy and try again with that.

If the finished PDF is too large

Merging bundles pages; it does not shrink them. The new PDF contains all pages of all source files and is correspondingly large. It doesn’t have to equal exactly the sum of the individual sizes, because the file is rebuilt. But this does not specifically make it smaller.

So after saving, read the actual file size and compare it with your recipient’s requirement. With the upload calculator, you can check total size and page limit before you upload or send the file.

If the file is too large, it’s best to proceed like this:

1. First, find out whether the recipient really needs all pages. If not, you can remove unneeded pages from the source files, for example blank back pages or duplicate scans, and then merge them again. If the complete document is required, all pages stay in.
2. If the merged PDF is at most 50 MiB, you can reduce the size of the finished PDF. To do this, open the compression tool and select the saved file there. Afterwards, you’ll see whether the result has actually become smaller. Then compare the original and the result for legibility. Only if both are fine do you save the smaller copy. If the compression finds no smaller valid version, you get your file back unchanged. Then your remaining options are fewer pages or source files reduced in size beforehand.
3. If it is larger than 50 MiB, the compression tool will not accept it, even though merging allows results up to 100 MiB. In this case, combine fewer files or pages at once, reduce the size of the individual source files before merging, or use an installed PDF program.