In-memory processing
Merge PDF runs as JavaScript inside this tab.
Never uploaded
Safe for financials, contracts and NDAs.
No caps or sign-ups
File size is limited only by device memory.
Merge PDFs to combine invoices, scanned pages, chapters or signed forms into one file that is easier to send, print or archive. Files are joined in the order you add them.
Also known as Combine PDF.
No. Merging copies the original pages into a new PDF without re-rendering them, so text, images and vector graphics keep their exact quality. Bookmarks and form fields from the source files may not carry over.
Yes. Merge PDF runs entirely inside your web browser using JavaScript, so the file never leaves your device. It is safe for confidential documents such as contracts, financial records and IDs.
There is no fixed limit, because the file is processed on your own device. Very large files depend on your device's available memory; a modern laptop or phone handles hundreds of megabytes.
Yes. ZapConvert runs in any modern browser, including Safari on iPhone and iPad and Chrome on Android, with nothing to install. You can add several files at once and download them together as a ZIP.