What is Merge PDF?
Merge PDF combines two or more PDF documents into a single file. You choose the order, and every page of every document is copied into the result exactly as it was: text stays selectable, links and vector graphics keep their quality, and nothing is re-compressed or converted to images. It is the quickest way to turn a pile of loose files – scanned receipts, chapters of a report, signed annexes – into one tidy document you can send, print or archive.
Your files never leave your device
Most online PDF mergers upload your documents to a remote server. This one does not. The merge runs inside your browser with the open-source pdf-lib library, in a background worker so the page stays responsive even with large files. Your documents are read from your disk, combined in memory and handed back to you as a download. Nothing is uploaded, logged or stored, which makes the tool safe for contracts, invoices, medical reports and other confidential paperwork. You can even disconnect from the internet once the page has loaded.
How to merge PDF files
- Drag your PDF files onto the drop zone, or click Choose files and select several at once.
- Put them in the right order: drag each row to its place, or use the ↑ and ↓ buttons (handy on phones and with the keyboard). Remove a file with ✕.
- Click Merge PDF. When it finishes, download the combined document.
Each file is checked when you add it. If a document is damaged or protected with a password, it is rejected with a clear message instead of producing a broken result. For password-protected files, use Unlock PDF first if you know the password.
Practical examples
- Job applications: join your cover letter, CV and certificates so recruiters receive one file.
- Expense reports: combine scanned receipts in date order before submitting them.
- Reports and theses: assemble chapters exported separately from different programs.
- Contracts: attach signed annexes to the main agreement in the order required by the other party.
Frequently asked questions
Is there a limit on the number of files?
There is no fixed number. Each file can be up to 100 MB and 500 pages. Because the work happens on your device, very large merges depend on your computer's memory; a modern laptop handles hundreds of pages comfortably.
Will bookmarks and form fields be kept?
Pages, their content, annotations and links are copied. Document-level features such as the bookmarks outline and interactive form fields are not carried over, because they belong to each original file rather than to its pages.
Does merging reduce quality?
No. Pages are copied object by object, so the result looks identical to the originals. If you need a smaller file afterwards, run it through Compress PDF.