Free, runs entirely in your browser — no sign-up, no file upload to a server.
What does Merge PDF do?
It combines multiple PDF files into a single document, in the order you arrange them.
How many files can I merge?
There's no fixed limit — add as many PDFs as you need; very large batches just take a little longer since merging runs in your browser.
Can I merge password-protected PDFs?
No — a password-protected or encrypted source PDF will cause the merge to fail. Remove its password first with the Unlock PDF tool.
Where are my files processed?
Entirely in your browser (via the pdf-lib library) — no PDF is uploaded to a server.
How do I report a problem or request a feature for this tool?
Use the Contact / Feedback page — select "Merge PDF" as the related tool so we know exactly which tool you mean, then describe the bug or the feature you'd like to see.