Merge PDF Files — Combine Multiple PDFs Into One

You can merge up to 20 PDF files in a single operation. If you need to combine more, merge them in batches: merge the first 20 into one file, then merge that result with the next batch. There is no limit to how many times you can use the tool.

No. The tool uses PDF-Lib to combine files at the document structure level, without re-encoding any content. Text remains selectable and searchable, images stay at their original resolution, and fonts are preserved. Bookmarks, annotations, and form fields from the original documents are also retained in the merged output.

Yes — each page keeps its original dimensions, whether A4, Letter, landscape, or any custom size. If your source PDFs have different page sizes, the merged PDF will have mixed page sizes, which is fully valid and works in all PDF viewers. If you need uniform page sizes, consider printing to PDF with a fixed paper size first.

Your files are uploaded to our server for processing and deleted immediately after you download the merged result. We do not store, index, or analyze your documents. For highly sensitive documents, consider using a desktop PDF tool that processes files locally.

Merging combines multiple PDFs into one document in the order you specify. Appending specifically means adding pages at the end of an existing PDF. Our tool merges PDFs in your chosen order, which covers both use cases: you can place any file first, making it equivalent to either merging or appending depending on how you arrange the files.