Private organize tool
Merge PDF Files
Join PDFs locally, in the order you choose. Processing stays in your browser.
More file tasks
Use a practical PDF preflight checklist covering page size, bleed, fonts, images, color, page order and final proofing.
How it works
A useful result,
without the upload.
Combine multiple PDFs in a chosen order and download one merged document without uploading confidential files. The file is decoded and processed inside this browser tab, so File Preflight never receives its contents.
Worked example
Combine a cover PDF, 12-page workbook and answer key into a single 15-page download.
How to use the Merge PDF Files
- Choose two or more PDF files using the file picker.
- Reorder files by dragging or using the up/down buttons.
- Remove any unwanted files using the delete button.
- Click the merge button to combine files in the selected order.
- Download the merged PDF and verify the page order.
What happens under the hood
This tool uses pdf-lib to merge PDFs locally. It copies source pages into a new document without rasterizing their content. Document-level metadata, bookmarks, signatures and interactive behavior are not guaranteed to survive. Review the merged file and retain the originals; no file content is uploaded.
Before you send the file
- PDF forms, signatures and advanced document features may not survive every merge workflow.
- Very large documents require more device memory.
- Review the downloaded page order before distribution.
Frequently asked questions
Do merged PDFs retain form fields?
Not always. Complex form fields, JavaScript, and interactive features may not survive the merge process and could be lost.
Can I merge password-protected PDFs?
This merger does not accept encrypted PDFs or provide a password prompt. Export an unencrypted copy from the source application only if you are authorized to do so, then merge that copy.
What is the maximum file size for merging?
Very large documents (over 100 MB) may require substantial browser memory. For best results, merge smaller batches or optimize source files first.
Will the merged PDF have bookmarks?
Bookmarks from source files are not preserved in the current merge workflow.
Keep an untouched original and inspect the downloaded file before replacing any production asset. Closing this tab removes the selected files from the tool.