Merge PDF combines two or more PDF files into a single document, in whatever order you choose. It's useful for joining a signed contract with its appendices, sending one application instead of five attachments, or collecting scanned receipts into one file for your accountant. The merging happens inside your browser, so your documents are never uploaded to a server.
How to merge PDF files
- Drop your PDF files onto the tool, or click Choose files and select them. You can hold Ctrl (Cmd on a Mac) to pick several at once.
- Check the preview of each file's first page to make sure you have the right documents.
- Put the files in order with the arrow buttons, or click Sort by name to order them by file name.
- Click Merge PDFs.
- Click Download merged PDF to save the combined file.
What stays the same after merging
Pages are copied into the new file exactly as they are, not re-rendered or re-printed. That means:
- Text stays sharp and selectable. You can still search, highlight and copy text in the merged PDF.
- Images keep their original quality. Nothing is re-compressed.
- Page sizes are kept. An A4 report and a US Letter form can sit in the same PDF, each at its own size, and landscape pages stay landscape.
- Web links keep working. Links to websites inside the pages are preserved.
The merged file is usually about the size of all the input files added together.
What doesn't carry over
A PDF can contain more than its pages, and a few of those extras are tied to the original file's structure:
- Bookmarks (the outline shown in a PDF reader's sidebar) are not copied into the merged file.
- Fillable form fields may look right but stop being editable. If you need the answers in a form to survive, fill it in and save or "flatten" it before merging.
- Accessibility tags used by screen readers are not carried over.
- Links that jump to another page in the same original document may no longer work.
For most everyday merging, such as scans, invoices, reports and signed documents, none of this matters. For long reports that rely on bookmarks, check the result before you send it.
Password-protected PDFs
The tool can't merge files that are encrypted, and it will tell you which file is the problem. There are two kinds of PDF password:
- An open password stops the file being opened at all without the password.
- A permissions password lets anyone open the file but restricts printing, copying or editing.
Either one prevents merging. If the file is yours, open it in your PDF reader, enter the password, and save a copy without protection. Then add that copy here.
Tips for a tidy merged PDF
- Name files in order before you start, for example "01 Cover.pdf" and "02 Report.pdf". Then Sort by name puts them straight into sequence. Sorting treats numbers sensibly, so "file 10" comes after "file 9".
- Remove pages you don't need first. If you only want part of a document, use Split PDF to extract the pages you need, then merge the result.
- Turn photos into PDF pages first. To add photos or scans saved as images, convert them with JPG to PDF, then merge.
- Check large files on a computer. Everything runs in your browser's memory, so very large documents, hundreds of megabytes in total, work best on a desktop or laptop rather than a phone.
Merge PDF FAQ
Is this PDF merger free?
Yes. There is no signup, no watermark, and no limit on how many files you combine or how often.
Are my PDF files uploaded to a server?
No. The files are read and combined by your web browser on your own device. Nothing is sent to Lembog or anyone else, which also means the tool works with confidential documents.
How many PDFs can I merge at once?
There is no fixed limit. The practical limit is your device's memory. Dozens of normal documents are fine on any modern computer or phone.
Can I change the page order inside a file?
This tool orders whole files. To use only some pages of a file, or to change their order, extract them in the order you want with Split PDF, which saves pages in the order you type them. Then merge the result.
Will merging reduce the quality of my PDFs?
No. Pages are copied, not re-rendered, so text, vector graphics and images stay exactly as they were.
Why does the tool say my file can't be merged?
The file is either password-protected or damaged. Protected files need their password removed first, as described above. For a damaged file, try opening it in your PDF reader and saving a new copy, which often repairs small errors.
Can I merge PDFs on my phone?
Yes. The tool works in mobile browsers on Android and iPhone. Tap Choose files to pick PDFs from your device or a cloud drive such as iCloud Drive or Google Drive.