Batch Merge PDFs

Drop in a stack of PDFs and merge them into groups — by basename prefix or by chunk size — output as one merged PDF per group inside a .zip.

Your files never leave your browser. All processing happens on your device — nothing is uploaded.

1. Upload your files (min 2)

Need at least 2 files (have 0).

How does the Batch Merge PDFs work?

Merge many PDFs in groups — not all into one. Choose Prefix mode if your filenames share starting words ("invoice-2025-jan-1.pdf, invoice-2025-jan-2.pdf, receipt-2025-jan-1.pdf" merges into invoice.pdf and receipt.pdf). Choose Chunk mode if you want every N files combined regardless of name (good for "combine every 10 scanned pages into one PDF" workflows). The output is a single .zip with one merged PDF per group. Use the regular Merge PDF tool if you only need one combined output.

🔒 Security & Privacy

All processing happens on your device. Your files never leave your browser, never touch our servers, and are not stored anywhere. Close the tab and the file is gone.

📱 Use it on any device

Works in any modern browser — Mac, Windows, Linux, iPhone, Android, and tablets. No installation, no app to download. Just open the page and start.

⚡ Quick & easy

Drag, drop, click. Most files process in seconds, not minutes. No watermarks added to your output, no per-day limits, and the tool always shows the result before asking you to download.

🎁 Always free, no signup

Free to use, every time. No account creation, no email required, no “trial” that converts to a paid plan. We make money from ads so you don’t have to pay.

Frequently asked

The starting run of letters / digits / underscores in the filename, before the first dash, dot, or space. So "invoice-005.pdf" and "invoice_006.pdf" both group under "invoice".

For heavier PDF workflows

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