About
Justools

Free, private browser tools for everyday tasks.

PDF tools

  • Merge PDF
  • Split PDF
  • Organize PDF
  • Rotate PDF
  • Delete PDF Pages
  • Add Page Numbers
  • Watermark PDF
  • Image to PDF
  • PDF to JPG
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  • Remove PDF Password
  • Compress PDF
  • Protect PDF
  • PDF to Text
  • Crop PDF
  • Flatten PDF

Image tools

  • Image Converter
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  • Image Cropper
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  • SVG Optimizer
  • Resize Image
  • Compress Image
  • Remove Background
  • Image to Text

Developer tools

  • JSON Formatter
  • CSV to JSON
  • Hash Generator
  • Base64
  • URL Encode
  • Timestamp Converter
  • Diff Text
  • Case Converter
  • Word Counter
  • Color Contrast
  • Unit Converter

Utility tools

  • QR Code Generator
  • Trim Video
  • Merge Video
  • Screen Recorder
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Creative tools

  • Coloring Pages
  • Graph Paper Generator
  • Spin the Wheel

Calculators

  • Cost of Raising a Child Calculator
  • Calorie Deficit Calculator
  • BMI Calculator
  • Age Calculator
  • Date Calculator
  • City Time Converter
  • Scientific Calculator
  • Fraction Calculator
  • Cost of Living (20 countries)
  • Budget Planner
  • Pay Raise Calculator

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© 2026 Justools. General information only, not financial advice.

Protect PDF

Add a password so a PDF cannot be opened until the recipient enters it.

Office and document supplies

Desktop Document & Office Gear

Office Essentials

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Other useful tools

Free tools that often go together. Everything runs in your browser.

  • PDF toolsRemove PDF PasswordSave an unprotected copy
  • PDF toolsCompress PDFReduce PDF file size
  • PDF toolsFlatten PDFFlatten form fields
  • PDF toolsWatermark PDFText or image watermark
  • PDF toolsMerge PDFCombine PDFs in your browser
  • PDF toolsSplit PDFExtract pages or split to ZIP

How to use this tool

  1. Upload one PDF.
  2. Enter the password people should use to open the protected copy.
  3. Click Protect PDF and download the encrypted file.

Frequently asked questions

What does Protect PDF do?▾

Protect PDF adds a password to a PDF so it cannot be opened without entering that password first. This differs from editing permissions: once someone has the password, they can usually view, print, and edit the file depending on their PDF reader. People use it before emailing sensitive documents such as tax returns, payslips, medical records, or signed contracts, since email itself is not always secure and attachments can be forwarded on without your knowledge. HR departments protect employee files before sending them between offices, accountants protect client tax documents, and freelancers protect invoices that include banking details. The password acts as a simple lock: whoever needs the file also needs the password, usually shared through a separate channel such as a phone call or text message.

Who typically password-protects a PDF?▾

Accountants protect client tax returns before emailing them. HR teams protect offer letters and payslips that include salary and bank details. Freelancers protect invoices before sending them to clients, and families protect scanned passports or medical records before uploading them to a shared drive. Anyone sending a PDF with information they would not want a stranger to open right away can add a password first, especially when the file travels through email or a shared drive before reaching the right person.

What encryption does it use?▾

The tool uses a lightweight browser-compatible PDF encryption library that applies 128-bit PDF password protection.

Is this the same as secure document sharing?▾

No. Password protection helps prevent casual opening, but you should still share sensitive files and passwords carefully, for example through separate channels.

Can Justools recover my password?▾

No. We do not see or store the password. Keep a copy somewhere safe if the file matters.

Can this crack or remove a PDF password?▾

No. This page only adds a password to your own PDF. It does not guess, crack, or remove passwords. Use Remove PDF Password if you already know a file's password and want to take it off.

Is the password uploaded to your servers?▾

No. The password is used only in your browser while the protected PDF is created. We do not transmit or store it.

What are the file limits?▾

One PDF up to 25 MB per job.

Processed locally in your browser. Your files are never uploaded to our servers.