IT · Free
Merge PDF Files
Merge multiple PDFs into a single document in the order you want, e.g. attaching supporting documents for a payment request, combining ID card copies with a form, or joining several parts of a report. All files are processed in your browser, with no upload.
Your files are not uploaded anywhere — every step runs in the browser on your own device. No file is sent to the Office.in.th server or to any third party, so it is suitable for documents with personal data or internal company documents (in line with PDPA guidance). When you close this page, the files disappear from memory immediately.
Drag PDF files here
You can choose several files · 50 MB in total at most
Order of files to merge
Add at least 2 files. Drag items to change the order, or use the arrow buttons. Files are merged from top to bottom.
How to use
- Drag PDF files into the box, or click "Choose files from device" (multiple files can be selected)
- Arrange the order by dragging items or pressing the arrow buttons, and remove unwanted files with the ✕ button
- Click "Merge and download" and the system creates merged.pdf on your device
Frequently asked questions
Are my files uploaded to a server?
No. Merging runs entirely in the browser on your device. We have no channel on our server for receiving PDF files at all, so it suits documents containing personal data or confidential company documents.
How large can the merged files be?
The total file size must not exceed 50 MB and no more than 60 files at a time, so the browser does not run out of memory. If your files are larger, merge them in several rounds.
Why does the system say it cannot read my file?
The file may be password-protected or damaged. Please remove the password first, then try selecting the file again.
Does the merged file lose quality?
No. The system copies the pages directly and joins them together, so text, images and fonts stay the same. However, any existing digital signature in the original files may no longer be verifiable after merging.