Merge Settings
File Order
How this PDF Merger works
This tool runs on pdf-lib, an open-source JavaScript PDF library, loaded directly in your browser tab as an ES module. When you add files, each PDF is read into memory with PDFDocument.load() so its page count can be shown immediately. When you hit "Merge PDFs", the tool creates a fresh PDFDocument, copies every page from each source file in your chosen order using copyPages(), and appends them into the new document with addPage(). The result is saved as a Blob and offered to you as a direct download — your original files never leave your device or touch a server.
- Reorder files with the Up/Down controls before merging — the final PDF follows that exact sequence.
- Page counts and file sizes are shown per file, so you can confirm what's included before merging.
- Because processing is entirely client-side, this works even for sensitive documents you wouldn't want to upload to a server.
- There's no file count limit and no file-size cap beyond what your browser's memory can handle.
When this tool is useful
- Combining scanned pages (from a scanner app or phone scans) into one document before submitting a form.
- Merging separate chapter or section PDFs into a single report or ebook.
- Joining an invoice and its supporting attachments into one file for email.
Frequently Asked Questions
No. The merging happens entirely in your browser using client-side processing. Your PDF files are never uploaded to any server, so they stay completely private.
You can add as many PDF files as you like. All pages from each file are combined in the order you arrange them into a single downloadable PDF.
Yes. Each uploaded PDF appears in a list where you can move it up or down or remove it entirely before merging, so the final document follows your chosen order.
No. The tool copies the original pages as-is into the merged document, so text, images, and formatting remain unchanged from the source files.
Yes, this PDF merger is completely free with no sign-up required. You can merge unlimited PDF files directly in your browser.
This tool uses the open-source pdf-lib JavaScript library to read, copy, and combine PDF pages directly inside your browser tab, without any server-side conversion step.