PDF Merger

Merge PDF Files Free: Fast, Private, and Unlimited

Combining multiple PDF files into one document is one of the most common document tasks in any office: collating a report with its appendices, joining invoices for an expense claim, merging chapters of a book, or bundling supporting documents into a single submission. Our free PDF merger handles all of it directly in your browser, with no server upload, no account, and no limit on how many files you can combine. All merging is performed using pdf-lib, an open-source PDF manipulation library that runs entirely in JavaScript inside your browser. Your files never leave your device. We keep zero logs.

How to Merge PDF Files Online

1. Upload your PDFs: drag and drop or click to browse. Select multiple files at once or add them one by one. Each file appears as a card in the merge list with its filename, size, and page count.
2. Reorder as needed: use the Move Up and Move Down buttons on each card to set the exact order you want pages to appear in the merged document. The order badge on each card updates automatically.
3. Set a filename: give your merged PDF a meaningful name before downloading.
4. Click Merge PDFs: a progress bar shows the merging status file by file. The download starts automatically when complete.

Page Count Loaded Automatically

As soon as each PDF is uploaded, its page count is read asynchronously using pdf-lib and displayed on the file card. You can see at a glance how many total pages your merged document will contain before you click Merge. If a PDF is encrypted or unreadable, an error is shown on the card and the merge button is disabled until the problematic file is removed.

Preserves Everything in Your PDFs

The merger uses pdf-lib's copyPages() method to transfer pages from each source PDF into the merged output. This preserves:

• All text: fully selectable and searchable in the output
• All images at their original resolution
• All fonts embedded in the source documents
• All internal links and annotations on individual pages
• Page dimensions: each page retains its original size (mixed page sizes are fully supported)

Mixed Page Sizes Supported

Unlike some PDF tools that force every page to the same size, our merger handles PDFs with different page sizes in the same batch. A mix of A4 portrait, Letter landscape, and A3 pages all merge into a single valid PDF where each page retains its original dimensions. This is ideal for combining documents created in different applications or regions.

Who Uses a PDF Merger?

• Office workers: combine reports, cover letters, and appendices into one submission file
• Finance teams: merge monthly invoices into a single expense PDF for accounting
• Students: combine assignment chapters, reference pages, and cover sheets into one document
• Legal professionals: collate case documents, evidence, and forms into a single filing
• HR teams: merge offer letters, policies, and onboarding documents into one package
• Architects & engineers: combine drawings, specifications, and schedules from multiple PDF sources

Handles Encrypted PDFs Gracefully

If a PDF in your upload batch is password-protected or encrypted, pdf-lib will detect this when it attempts to read the page count. The file card shows a clear error message and the Merge button is disabled until the problematic file is removed. This prevents silent failures where an encrypted PDF would produce a corrupt or incomplete merged output.

Free, Private & No Limits

The PDF merger is completely free to use with no account and no usage limits. Merge two PDFs or twenty: there is no cap on file count or total page count. All processing happens in your browser. Your PDFs are never sent to our servers, and we keep absolutely no logs.