Merge PDF
Combine the pages from two or more PDF files into one new PDF. Files are processed in the order shown after selection; you can add, replace, or remove files before merging, but this interface does not provide drag-and-drop reordering.
What the merger combines
The merger copies every page from each source PDF into a newly created document. It is intended for page-level combination, such as placing a cover sheet before a report or joining separately scanned sections.
Because a new document is assembled from copied pages, document-level features are not guaranteed to transfer exactly. Review outlines, attachments, forms, scripts, signatures, links, metadata, and accessibility structure when those features matter.
How to use this tool
- Select PDFs: Choose at least two PDFs. Their displayed order determines the page sequence in the result.
- Review the list: Add, replace, or remove files. If the order is wrong, clear and select them again in the intended sequence.
- Merge: Start the merge and keep the tab open while each source is loaded and its pages are copied.
- Inspect the download: The result downloads automatically and can be downloaded again. Check page order and any interactive features before discarding originals.
Input and output
Input
- Two or more PDF files
- A password entered in the page only when the shared PDF workflow detects a protected document
Output
- One PDF named merged_document.pdf
How pages are copied into the new PDF
Create a destination
pdf-lib creates a new empty PDF in browser memory.
Copy pages in sequence
For every selected file, all page indices are copied and appended to the destination.
Serialize and download
The destination is saved as a new PDF blob and passed to the browser download flow.
Combining a cover sheet and report
- Scenario
- A signed cover sheet must appear before a twelve-page report.
- Action
- Select the cover first, confirm the displayed order, and merge.
- Input
- cover.pdf followed by report.pdf
- Expected result
- The new PDF should contain the cover page followed by every report page. The visual pages should be checked because digital-signature validity and document-level structures are not promised.
PDF merge limitations
- The current interface does not provide drag-and-drop file reordering.
- All source pages are included; it does not select page ranges during merging.
- Total source size and page complexity are limited by browser memory, with no fixed size threshold enforced.
- Document-level bookmarks, portfolios, attachments, forms, scripts, signatures, metadata, and tagged-PDF structure may not survive page copying as expected.
- A digital signature from a source should not be assumed valid in the newly assembled file.
- Malformed or unsupported encrypted PDFs can fail to load.
Frequently Asked Questions
Can I merge only selected pages?
Not in this merger. It appends every page from every selected PDF. Use Extract PDF Pages first when only part of a source is needed.
Will bookmarks and digital signatures remain valid?
Do not assume so. The implementation creates a new PDF and copies pages; document-level navigation and cryptographic signatures require separate verification.
How do I change file order?
The merge follows the displayed selection order. The current interface can add, replace, or remove files but has no drag-to-reorder control.
Related tools
Split PDF
Turn each page of a PDF into a separate one-page PDF.
Extract PDF Pages
Create a PDF containing selected pages before merging it with another file.
Organize PDF Pages
Build a new PDF from pages in a specified order.
Compress PDF
Try to reduce image-heavy output after the page sequence is correct.