Organize
Merge PDF files
Combine two or more PDFs into one document. Upload your files, drag to set the order you want, and click Merge. The output is a single PDF containing every page from every file in the order you arranged them. All processing runs in your browser; no files are sent to a server.
Drop PDF files here
or click to browse · PDF only · multiple files allowed
How it works
- 1
Upload your PDFs
Drop two or more PDF files onto the upload area, or click to browse. Files are read immediately in your browser — nothing is sent to a server.
- 2
Arrange the order
Drag file rows up and down to set the page order. The number badge next to each row shows its position. Pages appear in file order within each file.
- 3
Merge
Click Merge. pdf-lib reads each file, copies pages in the order you set, and builds a new PDF in your browser memory.
- 4
Download
When the merge is complete, click Download PDF. The file is saved directly to your device. It is not uploaded or stored anywhere.
Common uses
- Combine a cover letter and CV into one PDF
- Bundle multiple invoices into a single file for an accountant
- Assemble a multi-chapter document from separate exports
- Package supporting documents into one attachment
Limitations
- Encrypted or password-protected PDFs cannot be merged.
- Very large files may hit browser memory limits.
- Merge preserves page content but may not preserve embedded scripts or interactive form fields from all sources.
Input
PDF files only. Each file must be a valid, unencrypted PDF.
Output
A single merged PDF file ready to download.
Frequently asked questions
There is no hard limit on the number of files. In practice, browser memory limits the total uncompressed page data. If you hit memory errors, merge in smaller batches and then re-merge the results.
Page content and embedded images are preserved. Interactive elements such as form fields, bookmarks, and JavaScript actions may not survive the merge depending on how the source PDFs were produced.
No. The merge runs entirely in your browser using pdf-lib. Your files never leave your device.
No. Encrypted or password-protected PDFs are rejected with an error message. Remove the password first using a trusted tool, then merge.
Pages appear in the order of the files in your list. Drag file rows to reorder them before merging. Within each file, pages appear in their original order.