Merge PDF files without uploading them
Combine PDFs into one document right in your browser. Nothing is sent to a server, and form fields and internal links survive the merge.
Runs on your device · 0 bytes uploaded
Drag files to reorder, or use the arrows.
How to merge PDF
- Add two or more PDF files — drag them in or click to choose.
- Put them in order with the ↑ and ↓ buttons.
- Click “Merge PDFs” and download the combined file.
Private by design — and you can check
Your files are never uploaded, because there is nowhere to upload them to.
- No upload step existsFiles are read and written inside this browser tab. There is no server that could receive them.
- The browser enforces itThis page’s Content Security Policy only allows connections back to this site, which serves nothing but the app itself.
- See for yourselfOpen developer tools, watch the Network tab and run a job: no request carries your document.
- Open sourceEvery line is on GitHub, built on qpdf, pdf.js & pdf-lib.
Frequently asked questions
Are my files uploaded anywhere?
No. Fizzdoc does the work inside your browser tab, using open-source engines compiled to WebAssembly and JavaScript. Your file is read from your device, processed locally, and the result is saved straight back to your device. You can check this yourself: open your browser’s developer tools, go to the Network tab, and run a job — no request carries your file.
Will bookmarks, form fields and links survive?
Form fields and internal links from every file are kept. Bookmarks from the first file are kept; bookmarks from the other files cannot be combined yet, and Fizzdoc tells you when that happens instead of dropping them silently.
Can I merge password-protected PDFs?
Yes. You are asked for the password on your device, and the merged file is saved without a password.
Is there a size limit?
There is no page limit. The size limit depends on your device’s memory — usually several hundred megabytes in total — and Fizzdoc tells you before starting if a job is too large for your device.
Is Fizzdoc free?
Yes. There is no sign-up, no watermark and no daily limit. Fizzdoc is open source under the MIT license.
More private tools
- Split PDFExtract the pages you need into a new PDF.
- Rotate PDFTurn sideways pages the right way, permanently.
- Delete PDF PagesRemove pages you don’t want to share.
- Unlock PDFSave a copy without the password you know.
- Protect PDFLock a PDF with a password and AES-256 encryption.
- Remove PDF MetadataStrip author, title, software and XMP details.
- JPG to PDFTurn photos and scans into one PDF.
- PDF to JPGSave every page as a sharp JPG image.