Merge PDF
Combine multiple PDF files into a single document
Combine multiple PDF files into a single document in seconds. Drag and drop your files, arrange them in order, and download the merged result. See our [processing model](/processing-model) for details on how this tool handles your files.
How to use Merge PDF
Upload your PDF files
Click the upload area or drag and drop your PDF files. You can select multiple files at once.
Arrange the order
Drag the file thumbnails to reorder them, or remove any file you don't need.
Click Merge PDF
The files are combined in your browser. No data is sent to a server.
Download the merged PDF
Click the Download button to save the combined PDF to your device.
Drop PDF files here
Add multiple PDFs to merge
Max 50 MB
What is PDF merging?
Merge PDF combines multiple PDF files into a single, unified document in seconds. Whether you have scanned pages, exported reports, or separate chapters, this tool joins them in the order you choose — no software installation or account required.
Merging happens client-side using PDF-lib (see our processing model for details), and the output is a standard, fully compatible PDF that opens in any PDF reader.
Merging PDFs is a common task across many workflows. Office professionals combine signed pages with a contract body, assemble meeting packets from multiple slide decks, or join monthly reports into a quarterly summary. Students frequently merge individual assignment pages or lab reports into a single submission file. Legal teams combine exhibits, affidavits, and cover sheets into unified court filings. The tool handles all standard PDF content including scanned pages, form fields, annotations, and embedded fonts without altering any of them.
For best results, ensure all source PDFs use the same page orientation. If some pages are sideways, use the Rotate PDF tool first. After merging, you can add page numbers to create a professionally formatted document, or compress the result if the combined file exceeds email attachment limits. Since each input file must be under 50 MB individually, very large documents can be merged in batches if needed.
Frequently asked questions
Is it safe to merge PDFs online?
Yes. The merge happens locally using PDF-lib in your browser tab, so your documents stay on your device. See our processing model for full details on how Utilavo handles files.
How many PDFs can I merge at once?
You can merge as many PDFs as you like. Each file must be under 50 MB, and the total size of all files should be manageable for your browser. Very large sets of high-resolution PDFs may require more time to process.
Will merging PDFs reduce their quality?
No. The merge operation preserves all content exactly as-is — text, images, vector graphics, and annotations are all retained at full quality. The tool does not re-render or compress any content during merging.
Can I merge password-protected PDFs?
Password-protected PDFs must be unlocked before merging. You can use the Unlock PDF tool on this site to remove the password first, then merge the resulting files.
Can I merge PDFs with different page sizes?
Yes. PDFs with mixed page sizes (for example Letter and A4, or portrait and landscape) merge without any issues. Each page retains its original dimensions in the combined output. If you need uniform page sizes, consider printing each source to a standard size before merging.
How do I merge PDFs and keep the bookmarks?
The merge operation preserves bookmarks (outlines) from each source PDF. They appear sequentially in the combined file's bookmark panel. If the source files do not contain bookmarks, the merged result will not have them either — consider adding page numbers for easy navigation instead.
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