Merge PDF
Merging PDFs means combining several PDF documents into a single file, keeping every page in the order you set. FreeToolsKit's merge tool runs the pdf-lib library inside your browser: you add files, arrange them, and download one combined document. Your files never leave your device — nothing is uploaded to a server.
Last updated: October 20, 2026
Drag and drop files here, or click to browse
PDF files only — add as many as you need
Your files never leave your device — processing happens in your browser.
Key takeaways
- PDFs are merged entirely in your browser with pdf-lib — files are never uploaded.
- Every file shows its page count before merging, and you can reorder files up or down the list.
- The merged document keeps the original pages exactly as they were — no re-rendering or quality loss.
- A summary shows the total pages and file size before you download the result.
How do you merge PDF files?
- Click to browse, or drag and drop two or more PDF files onto the panel.
- Check each file's page count in the list and remove anything you added by mistake.
- Use the up and down buttons to put the files in the order you want them to appear.
- Press “Merge PDFs” and watch the combined page count and size appear.
- Download the merged PDF from the result panel.
What is the Merge PDF used for?
- Combining a signed contract's pages into one file for emailing.
- Joining scanned documents — ID, certificates, transcripts — into a single application attachment.
- Merging monthly invoices or bank statements into one file for an accountant.
- Building one reading pack from several chapter PDFs for a course.
- Putting a cover letter and CV together as a single job-application document.
Frequently asked questions
Are my PDF files uploaded to a server?
No. Merging runs in your browser using the pdf-lib JavaScript library. Your documents never leave your device, are never stored and cannot be seen by anyone else.
Is there a limit on file size or number of PDFs?
There is no limit set by the tool. The practical limit is your device's memory — very large files (hundreds of megabytes) or dozens of big PDFs can strain a phone, but ordinary documents merge quickly.
Will merging change the quality of my pages?
No. Pages are copied into the new file exactly as they are — text, images and layout are preserved byte-for-byte. Merging does not compress or re-render anything.
What happens if one file is not a valid PDF?
That file is flagged with an error when you add it or when merging runs, and it is skipped from the result. Password-protected PDFs cannot be merged because their pages cannot be read.
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