When to use it
Use Merge PDF when each source file is already complete and you need one deliverable. If you need to delete, rotate, duplicate, or rearrange individual pages after assembly, move the merged result into Organize PDF.
Merge PDF
Combine multiple PDF files into one document.
Everything runs in your browserNo account requiredPrivacy-firstv1.0.0Updated Aug 5, 2026
Processed in your browser. Your files stay on your device and are never uploaded to Dockzio servers.
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Processing happens locally in your browser whenever possible.
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About PDF merge
Combine multiple PDF files into a single document without uploading anything. Reorder files before merging so pages appear in the order you need.
How it works
Dockzio copies pages from each PDF into a new file using pdf-lib in your browser. The original files stay on your device.
Limits
You can merge up to 20 PDFs at a time, with each file up to 25MB. Password-protected PDFs are not supported yet.
Page order
Use Move up / Move down to set the merge order. The first file in the list becomes the start of the merged PDF.
Privacy first
Everything is processed locally in your browser. Your documents are never sent to a Dockzio server.
Practical guidance
Build one controlled PDF from several source files
Merging copies pages into a new document in the order you specify. It is useful for assembling handoffs, appendices, packets, and production files without changing the originals.
Worked example
For a job packet, place cover-sheet.pdf first, proof.pdf second, and specifications.pdf third. A 1-page cover, 12-page proof, and 3-page specification file should produce a 16-page result in that sequence; verify the first page of each section after export.
Method and inputs
The only sequencing input is the ordered file list. Dockzio loads each source, copies its pages into a new PDF, and downloads the combined document. Source page dimensions are preserved, so mixed Letter, A4, and custom trim sizes can coexist.
Edge cases and verification
Encrypted files, malformed PDFs, very large image-heavy files, forms, bookmarks, and advanced interactive features may not combine as expected. Keep the originals and verify page count, order, page size, links, forms, and print appearance before distribution or production.
FAQ
Quick answers to common questions.
You can merge up to 20 PDF files at a time. Each file can be up to 25MB.
No. Everything is processed locally in your browser. Your documents never leave your device.
Yes. Use Move up and Move down in the file list to set the page order before merging.
Not yet. Unlock or remove the password before uploading, then try again.
Yes. Dockzio Merge PDF is free to use with no account required.
Learning Center
Guides related to Merge PDF
Short explainers that pair well with this tool — concepts first, then practice.
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- Merge vs Combine PDFs5 min read→
- Digital Signatures on PDFs7 min read→