Merge PDF
Runs locally
Drop in up to 20 PDF files, put them in the order you want, and download them combined into a single PDF. Nothing is uploaded — the files never leave your browser.
- Free to use
- No registration
- Runs locally in your browser
- Your data is never uploaded
Drop PDFs here, or click to choose files
Up to 20 files, 2.0 MB each
Your data is processed locally in your browser and is not uploaded.
Learn more about this tool⌄
How it works
Each file is read locally and checked against the real PDF file signature, not just its name or extension. The pages are then combined into a new PDF using pdf-lib, a dedicated PDF library — merging arbitrary, real-world PDFs correctly (fonts, images, page sizes and all) needs to parse each file's internal structure, which isn't something to hand-roll. The limits (20 files, 2 MB each) keep merging fast and comfortable in a browser tab.
Common use cases
- Combining scanned pages into one document
- Putting an invoice, a waybill and a customs form into a single PDF to print or file
- Joining chapters or sections that were exported as separate PDFs
Frequently asked questions
- Does this upload my files anywhere?
- No. Files are read and merged entirely in your browser — nothing is sent to a server.
- What are the limits?
- Up to 20 PDF files per merge, and each file must be 2 MB or smaller.
- Can I change the order?
- Yes. Use the ↑ and ↓ buttons next to each file before merging — pages are combined in that order.
- What if a file isn't really a PDF, or is corrupted?
- It's flagged in the list and excluded from the merge. Files are checked against the real PDF file signature, not just their name, before merging.