How it works
The PDF Merger combines multiple PDF files into a single PDF document — in your specified order — entirely in the browser. No upload, no file size limit imposed by a server, no watermark, no email required. The merged PDF is generated and downloaded directly.
Merging PDFs is one of the most common document tasks: combining individual invoice pages into a single submission, merging scanned contract pages into one document, combining chapters exported from different tools into a final report, or assembling a portfolio from separate project PDFs.
How to use it: click Add Files to upload multiple PDFs, or drag and drop them into the upload zone. Drag to reorder the files in the list — the merged PDF will contain pages in the order shown. Click Merge and Download. The single combined PDF downloads to your device.
Page ordering: the merged output contains all pages from all source PDFs concatenated in file order. If individual PDF files are multi-page, all pages from each file are included. For more granular page control (selecting specific pages, excluding pages, or reordering individual pages), use the PDF Reorder Pages tool.
File size: the merged PDF is the sum of the input PDF file sizes with minimal overhead (a shared catalog structure). No recompression of embedded images or fonts occurs during merging, so there is no quality loss.
Password-protected PDFs: PDFs with user password protection cannot be merged without unlocking them first. Use the Remove PDF Password tool to unlock them before merging.
Compatibility: the merged PDF is generated using pdf-lib, a pure-JavaScript PDF library. The output is fully compatible with Adobe Reader, Preview, and all PDF viewers.
Privacy: all PDF processing runs in the browser using pdf-lib. Your PDF files are never uploaded to a server.
Frequently Asked Questions
- There is no server-imposed limit because all processing runs in your browser. The practical limit is your device's available memory — merging 20+ large PDFs (100+ pages each) may slow down on devices with less RAM. Most merges of 2–10 standard documents complete in under 5 seconds.
- Password-protected PDFs cannot be merged without unlocking them first. Use the Remove PDF Password tool on this site to unlock each PDF, then merge them. Owner-password-protected PDFs (with editing restrictions but no open password) can usually be merged without unlocking.
- Hyperlinks and internal bookmarks within each PDF are preserved in the merged output. Cross-document bookmarks (bookmarks from one document pointing to a page in another) are resolved to the new page numbers after merging. Form fields from source PDFs are included but may need to be re-mapped if you need a unified form.
- No. The merge operation appends the raw PDF page streams from each source file without recompressing any embedded images, fonts, or graphics. There is zero quality loss. The merged file size is the sum of the individual files plus minimal overhead.