PDF Merger
PDFMerge multiple PDF files into one document in your browser. Drag files into order check page counts for each document merge then download one file all locally.
Related Tools
About PDF Merger
This PDF merger lets you combine multiple PDF files into one complete document in your browser, without installing Acrobat or uploading to a third-party site. Add files, drag to reorder their pages, preview each page and click merge to download the finished PDF. All processing happens locally via WebAssembly, so nothing is sent to a server — ideal for merging contract attachments, scanned pages, invoices and project reports. Two caveats worth knowing: pdf-lib copies page content during a merge, but interactive form fields, bookmarks and other complex structures may not survive fully; and password-protected PDFs must be unlocked first because the browser cannot crack protected documents. The output preserves each document's text layer for later searching and editing, and is roughly the sum of the inputs in size. Keep batches under about 50 files to stay within browser memory limits. A merged file is far easier to archive, share and review than a folder of scattered files, and is much safer for sensitive contracts than online merge services.
How to Use
- Open the PDF Merger tool
- Upload the PDF file
- Adjust the output options as needed
- Click the Process button; results appear in real time
- Copy or export the result
Use Cases
- Contract Attachments — Merge the main contract, appendices and addenda into one PDF for cleaner archiving and distribution to clients or legal.
- Project Reports — Combine cover, table of contents, body and appendices into a complete report with continuous page numbering.
- Scanned Pages — Merge per-page scan exports into a single document for easier storage and retrieval.
- Invoice Bundling — Group electronic invoice PDFs by month or project for smoother expense reimbursement and auditing.
- Study Materials — Combine lecture slides, papers and handouts into one PDF for centralised reading and printing.
FAQ
Are bookmarks or form fields preserved?
pdf-lib copies page content during merge, but interactive form fields, bookmarks and other complex structures may not be fully retained. Use desktop software if bookmarks are critical.
Does it support encrypted PDFs?
Encrypted PDFs must be unlocked before merging. The browser cannot decrypt protected documents - remove the password in the original tool first.
Can I reorder files?
Yes. After adding files, drag to rearrange; merging follows the list order.
Will the merged file be larger?
The output is roughly the sum of the input sizes, with minor variation due to rewritten metadata.
How many files can I merge?
There is no hard limit, but browser memory is finite. For best performance keep batches under 50 files to avoid lag.
Are files uploaded?
No. All merging runs locally in your browser via pdf-lib and WebAssembly, so files never leave your device, even sensitive contracts and IDs.