Send a confidential document
Encrypt a contract, payslip or medical report with AES-256 before it goes out by email or messenger.
Files never leave this device
Structure rescue
Repair a damaged PDF and see exactly what was recovered.
Rebuild broken cross-reference tables and truncated files on this device. The report says how many pages came back — and when a file is beyond repair, the tool says that too.
Reading files…
What it solves
A rebuild with an honest report.
Interrupted downloads, crashed scanners and buggy exporters leave PDFs with broken cross-reference tables or missing tails that viewers refuse to open. This tool has qpdf rebuild the file's structure in your browser and then reports plainly how many pages could be recovered. A file that opens fine gets an honest notice that there is nothing to repair, and a file that is too far gone is declared unrepairable instead of being turned into garbage.
Repair fixes structure, not content: pages whose data was never written cannot be conjured back.
Common uses
Work on your own locked file
Make an unlocked working copy of a PDF whose password you know, so you can merge, edit or print it without retyping the password.
Rescue a broken file
Rebuild a truncated download or a scan with a broken structure, and see exactly how many pages survived.
Quick guide
Protect, unlock or repair — always on this device.
- 01Add the PDF. It is read on this device only; nothing is uploaded anywhere.
- 02Set what the task needs: a new password to protect, the file's known password to unlock — a repair needs no input at all.
- 03Run the action. qpdf, compiled to WebAssembly, does the work inside your browser.
- 04Read the honest result report and download the new copy. The original file on your device is never touched.
Limits worth knowing
Honest about what it cannot do.
- 01
Unlock only removes protection when you provide the correct password. It cannot crack, bypass or recover a password you do not know.
- 02
If you protect a file and later lose the password, this tool cannot restore access. Store the password somewhere safe.
- 03
Some damaged files are beyond repair. When that happens, the tool says so instead of exporting a garbled document.
- 04
Very large files are limited by the memory this device can spend on a browser tab.
Frequently asked questions
Repairing a PDF — FAQ.
01Do my file and password leave this device?
No. qpdf runs as WebAssembly inside your browser, so the file and any password you type are processed on this device and sent to no server.
02Can it remove a password I don't know?
No. Unlock produces an unprotected copy only when you enter the file's correct password. It does not crack, bypass or recover unknown or forgotten passwords.
03How strong is the protection?
Protect encrypts with modern AES-256. The practical strength depends on the password you choose — and this tool cannot recover a lost one.
04What happens when a file cannot be repaired?
The repair reports exactly how many pages could be rebuilt. If the structure is too far gone, the tool declares the file unrepairable rather than producing garbage — and your original stays untouched either way.
Related tools
Keep working on the document.
01 / PDF
All PDF toolsUnlock PDF with the Known Password
Use the password you already know to decrypt a PDF locally and create an unlocked working copy.
Open tool02 / PDFCompress PDF
Reduce a PDF locally with clear quality profiles, predicted trade-offs and a before-and-after size check.
Open tool03 / PDFPDF Privacy Checker
Inspect metadata, forms, annotations, attachments, hidden layers, active actions and signatures before sharing a PDF.
Open toolShare this tool
Referencing this tool on a website?
Copy an attribution link. It is optional and does not change free access.