Merge PDF
Combine PDFs in order — files never leave your browser.
How merging works here
This tool uses the pdf-lib library running entirely in your browser: each PDF is read with the FileReader API, its pages are copied into a single new document, and the merged file is generated locally and downloaded. No server, no upload progress bar, no file-size caps imposed by someone else's free tier — the only limit is your device's memory.
Because files are never transmitted, this is safe for contracts, invoices and anything confidential — you can even disconnect from the internet after the page loads and it will still work.
FAQ
Can I reorder files before merging?
Yes — use the ↑ / ↓ buttons to arrange the list; pages appear in exactly that order in the output.
Are bookmarks, forms and annotations preserved?
Page content, links and annotations are preserved. Document-level outlines (bookmarks) from the original files are not carried over, as they reference whole documents rather than pages.
Is there a file size or count limit?
Only your device's RAM. Dozens of files merge fine on a normal laptop; very large PDFs (hundreds of MB) may be slow since everything is processed in memory.