PDF Merger

Merging happens on your device

This tool combines PDFs using the browser's own capabilities, so the files are read from your disk and never transmitted. That matters more for PDFs than for most formats, because the documents people merge are contracts, invoices, medical records, tax returns and scanned identity documents. Every online merger that uploads your files puts copies on someone else's server, usually with a retention window measured in hours, and their privacy policy is the only thing governing what happens in between.

Order is decided before you merge, not after

Pages are concatenated in the order the files are listed, so arrange them first. Reordering afterwards means splitting the merged document apart again. If your files are named with a numeric prefix, sorting by name usually gives the right sequence, but watch for the classic trap where file10 sorts before file2 because the comparison is alphabetical rather than numeric.

What merging preserves and what it drops

Page content, embedded fonts and images carry over intact. Interactive elements often do not survive cleanly: form fields from two documents can collide if they share field names, and digital signatures are invalidated by definition, because a signature attests to a specific byte sequence that merging changes. If a document is signed and the signature must remain valid, it cannot be merged.

Bookmarks and internal links may or may not be preserved depending on how the source files were produced. Links pointing to page numbers within their own document will follow the page to its new position; links pointing at absolute page indices will not.

File size after merging

The result is roughly the sum of the inputs, sometimes slightly less where identical embedded fonts are shared. Merging does not compress. If the combined file is too large for an email attachment, compress it separately afterwards rather than expecting the merge to help.