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CanaryPDF

Merge PDF Online — Combine Multiple PDFs into One, Free and Private

Merge PDF is a free, browser-based tool for combining multiple PDFs into a single document. Drag in your files, click Merge & Edit, and CanaryPDF stitches them together in the order you selected. The merged PDF opens in the page editor where you can reorder, delete, rotate, and save with optional password protection.

Your PDFs stay on your device. CanaryPDF processes everything in your browser using WebAssembly — there are no uploads to any server, no account required, and no usage limits. Closing the tab erases all working state.

Common reasons to merge PDFs: combining scanned contract pages into one signed agreement, consolidating receipts and invoices for expense reports, assembling a portfolio or report from multiple sources, or merging exported chapters into a single document.

After merging, the page editor gives you full control over the result. You can reorder pages with up/down controls, delete pages you didn't mean to include, rotate pages that came in sideways, and save the final PDF with or without password protection. The original files on your device are not modified — the merge produces a new combined PDF.

Encrypted PDFs are flagged at selection time. If one of your files is password-protected, the Merge PDF tool will point you to the Unlock PDF tool to remove the password first, then come back and merge the unlocked copy. This keeps the merge flow predictable and avoids confusing errors mid-process.

CanaryPDF's Merge PDF works on Chrome, Firefox, Safari, and Edge across desktop, tablet, and mobile. The tool is free for all features — no subscriptions, no usage limits, and no sign-up required.

How to Merge PDFs

  1. Open the Merge PDF tool — Go to canarypdf.com/merge-pdf to get started. Everything runs in your browser — your files are never uploaded.
  2. Select your PDF files — Click Select PDF Files or drag and drop two or more PDFs into the upload area. You can keep adding files until you have everything you want to combine.
  3. Click Merge & Edit — CanaryPDF combines the PDFs in the order you selected them and opens the merged result in the page editor. You can also remove a file from the list before merging.
  4. Reorder, edit, and save — In the page editor, reorder pages, delete unwanted ones, rotate, and save the merged PDF with optional password protection.

Frequently asked questions

How do I merge PDFs into one file?
Open the Merge PDF tool, select two or more PDFs, then click Merge & Edit. CanaryPDF combines them in the order you selected them and opens the result in the page editor so you can reorder or remove pages before saving.
Are my PDFs uploaded to a server when I merge them?
No. CanaryPDF merges PDFs entirely in your browser. Your files are never uploaded to a server. The merge runs locally using WebAssembly, and the combined PDF stays on your device.
How many PDFs can I merge at once?
There's no hard limit — you can merge as many PDFs as your browser can handle in memory. Most modern devices comfortably merge dozens of typical PDFs. Very large or image-heavy files may slow things down, since everything is processed locally.
Can I change the order of pages or PDFs?
Yes. After merging, you land in the page editor where you can reorder, delete, or rotate any page. PDFs are initially combined in the order you selected them on the merge screen.
What happens if one of my PDFs is password-protected?
Encrypted PDFs can't be merged directly. Use the Unlock PDF tool to remove the password first, then come back to merge the unlocked copy. The Merge PDF tool flags any password-protected file in your selection and points you to the unlock tool.
Can I save the merged PDF with a password?
Yes. The page editor's Save dialog lets you optionally add AES-256 password protection to the merged file. You can also save without a password if you don't need encryption.