Encrypt your private documents before sharing them. Our engine adds a password and flattens the PDF to prevent text copying. 100% Client-Side Privacy.
In a world where digital documents are constantly shared via email, WhatsApp, and cloud storage, protecting your sensitive information is more critical than ever. Whether you are sending financial reports, legal contracts, medical records, or confidential business invoices, sending an unprotected PDF leaves your private data vulnerable to unauthorized access and interception. ReduceSize PDF Protector allows you to easily add a strong, encrypted password to your document, ensuring that only the intended recipient can open and view it.
Most standard online PDF locker tools simply place a basic password layer over your existing file. However, once the recipient enters the password, they can freely highlight, copy, paste, or even digitally alter the text and signatures inside the document. We believe that is a huge security flaw.
Our tool introduces an advanced "Flatten and Encrypt" protocol. When you upload your document, our engine first converts every single page into a high-quality image layer (this is called flattening). After the pages are flattened, it locks the file with your chosen password. As a result, even when the authorized user opens the PDF, the text and signatures are securely baked into the page. No one can copy, edit, or tamper with your data.
Uploading highly confidential documents—like your PAN card details, business trade secrets, or personal bank statements—to a random third-party server just to encrypt them completely defeats the purpose of privacy. Unfortunately, that is exactly how most popular PDF websites operate.
ReduceSize operates on a strictly secure Client-Side Processing Architecture. When you select a document and enter a password, the entire encryption and flattening process occurs locally inside your device's web browser (utilizing your RAM). Your document, and the password you create, are never uploaded, transmitted, or stored on our servers. This guarantees military-grade offline privacy for your files.
Securing your files with ReduceSize is fast, free, and highly intuitive. Follow these simple steps:
Is it safe to lock my confidential legal documents here?
Yes, absolutely. Because our tool uses client-side JavaScript technology, your documents are processed locally on your own computer or smartphone. We do not have servers to intercept or view your files, ensuring complete confidentiality.
Can someone copy the text after they open the locked PDF?
No. Unlike basic password tools, our engine "flattens" the PDF. This turns the text into an un-selectable image layer, effectively preventing anyone from copy-pasting your content or stealing your digital signatures once the file is unlocked.
What if I forget the password I set?
Because we do not store your files or your passwords, we cannot recover a lost password for you. Please ensure you memorize the password or store it in a secure password manager before sending the file.
Does encrypting and flattening a PDF increase its file size?
Yes, because the flattening process converts text-based pages into high-resolution images to prevent copying, the final file size will increase. If the secured file becomes too large to send via email, you can use our PDF Compressor to reduce its size before sharing.