📚 Merge PDF Files
Combine multiple PDF files in your chosen order.
Process your document
Choose at least two PDFs. The files are merged in the order shown in your file picker.
No files selected.
How it works
The PDF is processed in your browser using the open-source pdf-lib library. Documents are not uploaded to OpenToolKit servers. A library script is initially downloaded from a third-party CDN; processing happens locally after it loads.
Limitations and privacy
Files are limited to 30 MB each and 20 files per operation. Memory-intensive documents may fail on older devices. Password-protected or malformed PDFs may not load. The output may not preserve every advanced feature in complex PDF documents. Review the downloaded PDF before relying on it.
For confidential files, remember that the library must load from the CDN on first use. Don't upload documents into other websites to troubleshoot this tool.
More PDF tools
Practical example: Merging class notes and reports
Suppose you have a two-page cover document followed by a ten-page report. Select both files in the desired order. The result should have twelve pages, with the cover first.
What to check before using the result
Merging combines pages but does not edit their contents. Check hyperlinks, interactive forms and any digital signatures in the output.
Frequently asked question
Can I combine PDFs with different page sizes?
Yes. The tool copies existing pages, so documents can contain different dimensions.
For more guidance, visit the OpenToolKit practical guides and check how processing works.