Merge PDF
Merge multiple PDF files online for free
Combine multiple PDF files into one complete document, arrange file order, preview the result, and keep the workflow local in your browser.
Drop PDF files here
Supports multiple PDF files
100% local
Everything is processed locally in your browser. Files are not uploaded.
Safe and private
Your files stay on your device for stronger privacy.
Free to use
Completely free, with no registration required.
Works everywhere
Supports Windows, Mac, iPhone, Android, and more.
How to merge PDF files
Upload PDF files
Choose one or more PDF files and add them to the upload area.
Arrange file order
Review the file order that will be used for the merged document.
Preview the result
Open the preview to review the merged PDF order.
Download merged PDF
Start the merge and download the finished PDF file.
Why choose FastToolAI Merge PDF?
- Simple workflow: a clear interface makes file ordering easy.
- Fast and efficient: browser-local processing is designed for quick results.
- Privacy protection: files are not uploaded to a server.
- High-quality merge: designed to retain original quality and formatting.
- Free to use: no registration or payment required.
- Compatible: works with modern browsers and common devices.
Common Merge PDF use cases
- Work reports: combine several reports into one complete document.
- Study material: collect reference documents for easier reading.
- Contracts: combine a contract with its supporting attachments.
- Project management: organize plans and project documents.
- Academic research: collect papers and supporting material.
Related PDF tools
Frequently Asked Questions
Will merging PDFs affect file quality?
No. Pages are copied directly into the merged PDF without rasterizing them.
How many PDF files can I merge?
You can merge up to 20 PDF files at a time.
How long does merging large files take?
Time depends on file size, page count, and your device performance.
Is there a merged PDF size limit?
The product rules recommend a total file size of no more than 200MB.
Can I change the file order?
Yes. Drag files to rearrange them; the list order is the final merge order.
Are my files stored or shared?
No. Files are read and merged locally in your browser and are not uploaded.
Can I merge PDFs on a phone?
Yes. The page layout adapts to desktop and mobile screens.
Can I edit the merged PDF?
The result remains a PDF file and can be processed with other PDF tools.