Password-protect a PDF before you send it
Email isn't a safe place for sensitive documents. Messages get forwarded, sent to the wrong person or sit in inboxes for years. Locking the PDF with a password means only the person you give it to can open it.
When to lock a PDF
Password-protect anything you'd be uncomfortable seeing in the wrong inbox: payslips and P60s, contracts, medical letters, HR documents, client reports, tax returns and scans of ID.
Many businesses also need to protect personal data in transit under GDPR. An encrypted PDF is a simple, widely supported way to do that without asking the recipient to install anything.
Key benefits
- Strong AES-256 encryptionThe same standard used by Adobe Acrobat. Without the password, the contents can't be read.
- Opens anywhereRecipients open it in any PDF reader, browser or phone by typing the password.
- Combine, then lockMerge several documents and protect the result in one export.
- No upload of the file or passwordEncryption happens on your device, so neither your document nor your password is sent anywhere.
How to add a password to a PDF
- Open Protect PDF and add your document. Add others if you want them in the same file.
- Type a password. Use the eye button to check it before you export.
- Export the PDF and try opening it yourself to make sure the password works.
- Email the PDF, then share the password a different way, such as by text message or a phone call.
Tips
- Never send the password in the same email as the file.
- Use a long passphrase, such as three or four random words, rather than a short password.
- There's no way to recover a forgotten password, so keep your unprotected original.
Questions
How do I put a password on a PDF for free?
Open Protect PDF in Think Pages, add the PDF, type a password and export. It's free, and the encryption happens in your browser.
Is PDF password protection secure?
With AES-256 encryption and a strong password, yes. The weak point is usually a short or guessable password, or sending it alongside the file.
Can I remove the password later?
Keep your original unprotected copy. Think Pages doesn't remove passwords from PDFs.
Tools for this job
More guides
- Privacy and securityWhy use PDF tools that don't upload your filesMost online PDF tools upload your documents to their servers. Learn why browser-based PDF tools are safer for contracts, payslips, medical letters and ID, and how to check.
- Home and everyday lifePut application documents into one tidy PDFCombine payslips, bank statements, ID and reference letters into one ordered PDF for a rental, mortgage or visa application. Private, free and nothing uploaded.
- Work and adminSpot changes between two versions of a contractFind what changed between two versions of a contract, lease or policy. Compare PDFs side by side for text and visual differences, and export a report. Private.