How to combine several PDF files into one document

When it’s worth merging PDF files

One file is more convenient than five attachments: it is easier to send, archive and print in the right order. The recipient doesn’t have to guess which document to open first, and you can be sure no attachment gets lost on the way. Merging is useful when submitting applications, sending offers, preparing a set of documents for your accountant or putting the chapters of a thesis together.

How to do it in PDFowo

1. Open the Merge PDF tool and drag your files into it or choose them from your drive. You can add many files at once.
2. Set the order. The pages appear as thumbnails that you can drag into place. The first one will be at the start of the result.
3. Click the merge button and download the finished document.

Everything happens in your browser. The files are not uploaded to a server, so you can safely combine documents with personal data, contracts or invoices. In the “Network” tab of your browser’s developer tools you can check that no request with file content goes out while you work.

How to get the order right

Before you click “merge”, think about who will read the result. The main document (the contract, letter or application) should come first, with the attachments in the same order in which you refer to them in the text. If the attachments are numbered (attachment 1, 2, 3), stick to that numbering. When in doubt, open the result and scroll through all of it before you send it.

If you need only some of the pages from one of the files, first cut them out with the Split PDF tool and merge afterwards. You can also remove unwanted pages from the finished document in the editor.

Common problems

• The file is password-protected. Protected documents can’t be merged until they are unlocked. If you know the password and have the right to the file, use the Unlock PDF tool.
• The result is very large. A merged file is roughly the sum of its parts. If it has to go by e-mail, shrink it afterwards with compression.
• Different page sizes. Scanned sheets, A4 pages and landscape drawings stay as they were in the result. If that bothers you, you can rotate selected pages in the editor.
• A damaged file. If one of the documents won’t load, try the Repair PDF tool first.

What to do with the finished file

After merging you can add page numbers, a watermark or a signature. It is also worth giving the file a meaningful name, e.g. “Rental-agreement-with-attachments.pdf”, rather than leaving “merged.pdf”. The recipient will appreciate knowing straight away what they have received.

Example: a set of documents for an application

Say you are submitting an application that needs a form, a copy of a payment confirmation and two certificates. They are all separate files: the form from an office program, the payment as a screenshot from online banking, the certificates as scans. Start with whatever isn’t a PDF yet: turn the screenshot into a PDF with the Convert to PDF tool. Then merge everything in the order the institution requires and give the file a name such as “Application-Smith-complete.pdf”. Finally, add page numbers so the official can refer to a specific page.

If the institution limits the file size, check it after merging and shrink it with compression if needed. That usually helps more than leaving out a page.

Frequently asked questions

Can I merge PDF files with photos?

Yes, but first convert the photos to PDF with the Convert to PDF tool (it supports JPG and PNG, among others) and only then merge them with the other documents.

How many files can I merge?

There is no daily limit. The practical limit is your device’s memory: very large files (hundreds of megabytes) work more slowly, especially on a phone.

Do bookmarks, tables of contents and forms survive merging?

The page content stays, but interactive elements such as bookmarks, internal links or form fields may not be kept. Check the document after merging.

Does merging reduce the quality of the document?

No. Pages are copied into the new file rather than saved again, so text and images usually stay exactly as they were.