PDF Merger
Combine multiple PDF files into one document, in any order you choose.
Files are merged entirely in your browser — nothing is uploaded anywhere.
Combine multiple PDF files into a single document in whatever order you choose — reordering pages before merging, without needing separate PDF editing software or an online upload service.
Merging happens entirely in your browser, so the files never leave your device — useful when the documents contain anything sensitive.
Why local processing matters for documents
Most free online PDF tools upload your file to a server, process it there, and hand back a download link. That's a reasonable engineering choice and a poor privacy one: the document sits on someone else's infrastructure, subject to their retention policy, their access controls and their breach risk.
PDFs are exactly the category of file where that matters — contracts, bank statements, medical letters, scanned passports, signed agreements. This tool uses a PDF library running inside your browser, so the file is read from your disk into your own tab's memory and never transmitted anywhere. You can verify that by opening your browser's network tab while merging: there are no upload requests.
What merging preserves and what it doesn't
- Page content, images and fonts carry over intact — the visual result is identical.
- Bookmarks and internal links from the source documents are generally not preserved in the merged file.
- Form fields may lose their interactivity, and duplicate field names across documents can conflict.
- Digital signatures are invalidated by merging, because the signed byte range no longer matches. That is correct behaviour, not a bug.
- Encrypted or password-protected PDFs must be unlocked before they can be merged.
- The merged file's size is roughly the sum of its parts; merging is not a compression step.
Frequently asked questions
- Is there a limit to how many PDFs I can merge?
- You can merge as many files as your browser's memory comfortably handles; very large batches of large PDFs may be slower depending on your device.
- Are my files uploaded to a server?
- No — the merge happens locally in your browser using client-side processing, so your documents are never uploaded anywhere.
- Can I reorder pages before merging?
- Yes — drag files into the order you want before merging; the final document follows that exact sequence.
- Will merging break a digitally signed PDF?
- Yes. A digital signature covers a specific byte range, so any modification invalidates it. If a signature must remain valid, keep that document separate.
- Can I merge a password-protected PDF?
- Not while it's encrypted. Remove the password using the application that created it or a PDF reader you trust, then merge the unprotected copy.
- Why is the merged file so large?
- Merging concatenates the source documents rather than recompressing them, so the result is roughly the sum of the inputs. Run it through a PDF compressor afterwards if size matters.