Merging PDFs used to mean installing desktop software or paying for a cloud subscription. PDFStream's PDF merge tool changes that — it runs entirely in your browser, processes everything locally, and delivers a perfectly combined document in seconds. The tool supports unlimited files. Upload two contracts you need to bundle, or fifty scanned invoices you want to consolidate — the process is the same. Drag and drop to reorder pages before merging, and click once to combine. The result preserves every page's original formatting, fonts, images, and bookmarks exactly as they appeared in the source files. Common use cases include combining multiple chapters of a report into one file for distribution, bundling supporting documents with a main contract, assembling a portfolio from separate design exports, or consolidating scanned pages from a multi-page form. The tool handles PDFs of different page sizes (A4, Letter, Legal) without forcing them to a common size. Because nothing is uploaded, merged files containing sensitive data — NDAs, financial statements, medical records — stay completely private. The file you download is the only copy that ever existed outside your original documents.

How-to

1
Select Files
Drag and drop your PDF files into the upload area or click to select them.
2
Reorder
Drag and drop the files in the list to arrange them in your desired order.
3
Merge
Click the 'Merge PDF' button.
4
Download
Download your merged PDF file.

Frequently Asked Questions

How many PDFs can I merge?▼

You can merge as many files as you want. Processing depends on your browser's memory, so very large files may take a bit longer.

Can I change the order?▼

Yes, just drag and drop the files in the list before merging.

Can I merge encrypted PDFs?▼

If the PDF is password-protected, please use the 'Unlock' tool first to remove the password.

Does merging reduce quality?▼

No, the original text, images, and layout are perfectly preserved.

Can I select specific pages before merging?▼

Merging is done file by file. If you only need specific pages, use the 'Extract' tool first.

What happens to bookmarks?▼

Bookmarks are preserved and merged into the new document.

Can I name the output file?▼

The default name is 'merged.pdf'. You can rename it easily in your file explorer after downloading.

Can I merge PDFs of different sizes?▼

Yes, files of different sizes (A4, Letter, etc.) are combined while maintaining their original sizes.

Is there a file size limit?▼

There is no hard limit, but please be aware that very large files might slow down your browser depending on your device's RAM.

Can I remove files after adding them?▼

Yes, you can remove individual files from the list before clicking merge.

Last Updated: August 6, 2026

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