PDF Merger

PDF

Combine multiple PDF files into a single document in the order you choose. Runs entirely in your browser: files never leave this tab.

Private by architecture: All processing is 100% client-side memory. Your data never leaves this browser tab.

Document Queue No files selected.

Drag and drop PDF files here, or click to browse

Merge Output & Assembly

Assembly Status

Queue at least two PDF documents on the left. The output PDF combines every page in your chosen sequence with original vector fonts, graphics, and annotations intact.

About This Tool

Combining a cover page, a contract body, and a signature page into one PDF usually means opening a desktop app or uploading files to an unknown server. This tool does the merge with pdf-lib running directly in your browser: it loads every uploaded file, copies all of their pages in the order you set, and assembles one output PDF in memory, with zero upload step.

For the reverse operation: pulling specific pages or chunks out of one PDF, use the PDF Splitter tool.

Key Features

Preserves vector fidelity: Vector graphics, fonts, text, and embedded photos copy exactly as rendered.
Interactive reordering: Move documents up or down to control exact output page sequence before assembly.
Multi-file batch queue: Drop 2 or more PDF documents at once to quickly assemble multi-part packets.
Page count metrics: Inspects and displays individual file page counts alongside aggregate totals.
100% client-side privacy: Execution runs strictly in browser memory with zero network egress.

Frequently Asked Questions

Are my PDFs uploaded to a server?

No. Files are read and merged in browser memory using the pdf-lib library running as WebAssembly/JS in this tab. Nothing is sent over the network.

Can I change the order the files are merged in?

Yes. Each uploaded file gets a row with up and down buttons: reorder the list before merging and the final PDF follows that exact order, pages intact.

Does merging affect page content, bookmarks, or form fields?

Page content is copied as-is via pdf-lib copyPages, which preserves vector graphics, text, and embedded images exactly. Document-level bookmarks/outlines and interactive form fields are not carried over: only page content.

Is there a limit on file size or page count?

Only what your browser memory can hold. Very large PDFs (hundreds of MB, thousands of pages) may be slow or run out of memory on low-end devices since everything happens client-side.

What if a file is password-protected?

Encrypted PDFs cannot be loaded by pdf-lib without the password and will fail to merge. Remove the password in a PDF editor first, then merge.