Password Protect PDF

Add an opening password without uploading the PDF

Financial statements, contracts, invoices, identification records and internal reports are often shared as PDFs. When the document must travel through email, cloud storage or removable media, an opening password can reduce the risk of a casual recipient reading the file without authorisation.

DraftFort encrypts the PDF inside your browser. The file and both password entries remain in temporary device memory; they are not submitted to DraftFort or placed in a server processing queue. The result is a separate AES-256 encrypted PDF. Your source file is not overwritten.

Password protection is useful access control, but it is not a digital signature, expiry system or complete document-rights platform. The tool explains those boundaries before it creates the copy.

How to password protect a PDF

1. Add an unencrypted PDF. Choose one file up to 100 MB.
2. Create a unique password. Eight characters is the minimum; a unique passphrase of at least 12 characters is recommended, and 16 or more is a stronger target.
3. Confirm the password. The two entries must match exactly, including uppercase letters, spaces and symbols.
4. Protect and download. DraftFort creates a new file ending in -protected.pdf.
5. Wait for verification. The browser checks the new bytes with your exact password before starting the download.
6. Test the copy. Open it in the PDF reader the recipient will use, enter the password, and inspect important pages, forms, links and attachments.
7. Keep the source and password safely. DraftFort cannot recover a password after the fields are cleared.

Avoid sending the protected PDF and its password in the same message. A password cannot help when the same unintended recipient receives both.

What AES-256 PDF protection means

DraftFort uses QPDF to write modern 256-bit PDF encryption. QPDF documents that 256-bit PDF encryption uses AES and recommends it instead of weak legacy encryption. DraftFort does not expose 40-bit, RC4 or compatibility modes that could encourage an insecure choice.

The password is used to derive access to the encryption key; it is not the encryption key itself. A strong algorithm therefore does not rescue a weak password. password, a birth date, a company name or a password reused on another account remains guessable.

The in-tool strength guide is deliberately simple. It considers length and character variety, but it cannot know whether a password was leaked, reused or based on personal information. A trusted password manager can create and retain a genuinely random password when appropriate.

Opening password versus PDF permission restrictions

This tool creates an opening password. A reader must supply it before the document content is displayed.

DraftFort deliberately leaves printing, copying, annotation, form and document assembly permissions available after opening. Those PDF permission flags are viewer-enforced preferences, not reliable digital-rights management. QPDF’s encryption documentation explains that software able to decrypt a PDF has the encryption key and can be modified to ignore permission restrictions.

That distinction prevents a misleading promise:

Once someone knows the opening password, they can read the document and may be able to copy, print, photograph or redistribute it. Share with recipients you trust and distribute the password through an appropriate separate channel.

What remains in the protected PDF

QPDF encrypts the PDF objects rather than painting each page into an image. Ordinary documents should retain:

• page count, order, dimensions and rotation;
• selectable and searchable text;
• fonts, vector graphics and existing image streams;
• links, bookmarks and annotations;
• interactive form fields and their values;
• document metadata; and
• embedded files.

Preservation is different from confidentiality review. Metadata, form values, comments and attachments are still present after an authorised reader opens the file. If author names, dates or XMP properties should not travel with the document, run Remove PDF Metadata before protecting the final copy.

PDF is a flexible format, so advanced scripts, unusual rights-management systems, damaged objects or producer-specific structures require manual review. Keep the original until the entire recipient workflow has been tested.

Digital signatures require a different workflow

A visible signature image is not the same as a cryptographic PDF signature. A cryptographic signature validates particular bytes in a particular document revision. Adding encryption writes a new PDF, so a former signature can become invalid even when its visual appearance remains.

Do not password-protect a signed source when continued signature validation matters. Ask the issuer for the correct protected-and-signed workflow, retain the authoritative signed original, and verify status in a suitable PDF reader.

DraftFort’s Sign PDF tool places visible text and signature marks. It does not issue a certificate-based cryptographic signature.

Already encrypted PDFs and changing a password

DraftFort rejects an already encrypted input rather than silently layering a second unknown security state over it. If you know an authorised opening password:

1. use Unlock PDF to create an unencrypted copy;
2. inspect that copy completely; and
3. return here to create a new AES-256 protected copy with the new password.

Unlock PDF does not guess, recover or crack passwords. If the current password is unknown, request a new copy from the owner or issuer.

Password recovery, storage and safe handling

DraftFort has no password account, recovery database or document backend. After an encryption attempt, both password fields are cleared from the page state and the isolated processing worker is terminated.

That privacy boundary also means there is no “forgot password” route. Before distributing the protected PDF:

• keep an unprotected original in an appropriately secured location;
• save the password in a trusted password manager or approved organisational system;
• verify the exact password against the downloaded copy;
• avoid reusing a personal or workplace account password; and
• decide how the intended recipient will receive the password separately.

Do not include the password in the PDF filename, document title, email subject or visible page text.

Private by design

Encryption is precisely the kind of operation that should not require sending the unprotected document and its new password to another company’s server. DraftFort loads the encryption engine into a temporary browser worker, uses an in-memory filesystem and returns the protected bytes directly to your device.

There is no account, upload, watermark or password log. The practical limit is your device’s memory and processor: a complex 100 MB PDF can require several temporary copies while it is encrypted and verified. Close memory-heavy tabs or use a computer if a phone cannot complete the operation.