Password Protect PDF Document without any Software

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File extension .pdf
Internet media type application/pdf
Description: The Portable Document Format (PDF) is a universal file format invented in 1993 year by Dr. John Warnock from Adobe Systems. This invention caused the paper-to-digital revolution, because the main purpose of inventing PDF was to make document look the same way as the original version on any computer or device.
Technical Details: Every PDF file has a structure with fixed formatting and information about fonts and graphic elements on each page of a document. PDF document may contain different types of elements, such as buttons, hyperlinks, bookmarks, or annotations. PDF documents have complete description of a fixed-layout flat document that makes PDF similar to vector graphics file formats.
Developed by ISO
Initial Release: 15 June 1993
Useful links:



Discover how to quickly put a password on a PDF 

How to password protect a PDF online

When sending documents with confidential information, you should be sure that only those who have access permission can view them. You can protect PDFs with passwords to restrict unauthorized viewers from opening them. Our cloud-based solutions will help you lock your documents in seconds. All you need to do is to upload a template, enter the code, and confirm it. Just make sure the combination is long enough and avoid using common words, dates, and sequences. 

Follow the instructions to quickly encrypt your PDF

  1. Choose a file from your device or the cloud.
  2. Type in a unique password to protect your PDF
  3. Use the eye icon to check the combination.
  4. Click Protect File Now!.
  5. Click on the file name and enter the code to preview it.
  6. Download the secured document.
  7. Choose Start over again to lock another PDF. 

Congratulations, you've securely protected your records. The service is free of charge, with no ads, and doesn’t ask you for installation or registration. Apart from putting a password on a PDF, the platform has other advanced tools to offer you. When you’ve finished encrypting, you can choose what to do next with the document: sign it with an e-signature, edit it, or use various sharing options. Get started with now!  

Watch the video tutorial on how to encrypt a PDF

Learn a fast and easy way to restrict access to your documents. We’ve prepared a quick video guideline to show how to add a password to protect your PDF files. Watch it now and keep your sensitive information safe.

Die Vergleichstabelle der herausragenden Merkmale

Aufgrund der Vielzahl der Konkurrenten im Web kann die Auswahl einer idealen Software eine Herausforderung sein - insbesondere, wenn Sie sie nicht genau mit den Alternativen vergleichen. Unsere Vergleichstabelle hilft Ihnen dabei, Ihre Lieblingslösung einfach auf Protect PDF Documents zu finden. Lernen Sie die Vorwärtsfunktionen von AltoPassword kennen.

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How to Password PDF Files

Add extra password to the documents with sensitive data using our online solution. Password your docs unlimitedly from the smartphone or computer.

How to add a password to PDF files online

The quickest way to protect your doc is to create a PDF password with the help of AltoPasswordPDF, a specialized software, that does just that. The service is cloud-based, so you don’t need to download anything from the Internet or take up your device’s memory. Plus, it lets you use the solution from any device: desktop, tablet, laptop and even smartphone. The only thing you need is a stable internet connection. 

Here is the list of steps you should follow in order to password protect PDF files for free:

  1. Open the online solution in your preferred web browser.
  2. Export a document from your device or cloud storage.
  3. Invent a password (it must consist of at least eight symbols).
  4. Check your encryption by clicking on the eye symbol.
  5. Download or upload the encrypted file wherever you need it.

This solution is perfect for those who have to deal with large amounts of paperwork. AltoPasswordPDF has no restrictions in terms of the number of documents you can password protect per day. Lock your documents, share them with others and be sure your data is intact and well-protected.

BackgroundHow to add a password to PDF files online

How to add a password to PDF files via Chrome

Chrome is one of the most widely-used Internet browsers nowadays all over the world. And there’s a good reason for it. The browser has versions that suit any device. Besides, it synchronizes a user’s search results across all his/her devices simultaneously. One of the most useful features Google Chrome possesses is the ability to install various extensions which makes the user experience easier and more convenient. A great example of one of these extensions is AltoPasswordPDF. It provides quick and reliable protection for your files.

Follow the steps below to keep your PDFs password-protected with the help of the Alto service for Chrome:

  1. Enter AltoPasswordPDF in the search field of Chrome’s Web Store.
  2. Add the extension to your browser and click on it.
  3. Click on the Choose File button and select the file you want to encrypt.
  4. Create a password in the corresponding field.
  5. Save the protected document.

The Alto extension has a user-friendly interface and saves your time because the whole process takes up less than a minute. Install the tool once and create as many PDF passwords as you need. 

BackgroundHow to add a password to PDF files via Chrome

How to password protect PDFs in Windows 

Windows OS doesn’t have a locking feature for documents by default. Therefore, you’ll need to set up a specialized extension in your browser or use a software tool for file encryption. Another option is creating encryption with MS Office Pack. Anyone who has Microsoft Office installed on their device can easily secure their documents with encryptions. Take note, that any file in Portable Document Format opened in Word, changes its format to .doc/.docx automatically. 

This is what you should do to add a password to a PDF file in Windows:

  1. Open the document you want to encrypt in MS Word.
  2. Select Save in the File menu.
  3. Indicate a folder where the document will be stored.
  4. Change the output format to PDF.
  5. Choose encryption from the list of options.
  6. Enter your encryption in the popup.
  7. Save the changes.

It’s noteworthy that you can lock your files with Microsoft Word only if the MS Office Pack (or at least MS Word) is installed on the device you’re using. Make sure you’ve downloaded the official version to avoid security issues. If you don’t want to install anything, an online tool like AltoPasswordPDF is a perfect solution for you.


How to password protect a PDF on a Mac

The main advantage of Mac OS compared to other operating systems is that it contains a lot more default features. Using these solutions, users can easily manage their files, including reading, editing, and locking them, etc. Regarding PDF passwords, the Preview app not only lets users view/change documents but also create encryptions for them. There are certain documents that contain confidential information, yet you might need to share them via email or other messengers. If you need to be confident that your sensitive data won’t get into the hands of frauds, follow the steps below:

  1. Open your PDF document and select File in the toolbar.
  2. Choose the Export option, then Encrypt.
  3. Create a password for your file by typing it in the corresponding field.
  4. Enter the encryption again to verify it.
  5. Click the Save button.

The whole process takes up less than a minute, yet you receive a fully password-protected PDF document. One more positive aspect about using the pre-installed feature is that you don’t need to search for a solution on the Internet or waste your time and money on installing it. 

BackgroundWith Preview on Mac

How to add a password to a PDF file without Acrobat

The Portable Document Format is primarily associated with the company Adobe. Being Adobe’s brainchild, PDF and all operations with this type of document can be managed via Adobe Acrobat, a software for reading, creating, printing and performing other manipulations with files in Portable Document Format. However, currently, there are a lot more options for managing this type of file including their password protection feature. Here is a list of variants you can choose from to password protect the PDF and the data it contains:


  1. Online tools. Choose cloud-based services, like AltoPasswordPDF, if you don’t want to install extra software onto your device.
  2. Browser extension. Add an extension for protecting documents with encryption to your browser and create passwords for as many files as you need.
  3. MS Word. Install Microsoft Word on your device, open the file and follow the easy instructions to encrypt your document.
  4. Mac OS. If you have the Mac operating system, you don’t need online tools or any extensions. The operating system already has a pre-installed protection feature that can be used through the Preview option.







BackgroundWith Adobe Acrobat Reader

How to Password PDF on the Phone

Sometimes the information in your files can be a little sensitive and need additional protection. What if someone stole your flash drive, smartphone or gained access to your email? With AltoPDF’s top of the line security, they won't be able to open your document without the password you set. If you want to password the PDFs on your smartphone, use One minute of your time for a lifetime of protection. 

  1. Open and click Choose File, then select a PDF you need secured. 
  2. Create a password for the PDF. 
  3. Tap Password File Now!.
  4. Download your document. 
  5. Explore pdfFiller’s useful features. 

When you add a password to PDFs, you can see its strength before you confirm it. Consider using strong passwords that can't be guessed. Avoid simple combinations like qwerty (12345, abcd).

Uploading your documents to Alto is a safe, secure and smart decision. We use the latest encryption methods to make web-based apps safer. We delete every file instantly after you exit the page, so no third party can steal your data. 

BackgroundHow to Password PDF on the Phone

How to Password PDF on iPhone

Password the PDF files you have on your iPhone, iPad or any other iOS or Android device with a password to save your data from outsiders. Add it to your documents without using specialized programs with AltoPDF. Follow these short steps to get your PDFs protected today: 

  1. Open in Safari or another browser. 
  2. Upload a PDF file you need to password. 
  3. Create your password. Use the tips to create a stronger one. 
  4. Tap Password File Now! 
  5. Download your document or edit and sign it in the pdfFiller editor. 

By using the protection function, each time someone opens the password-protected document, all readers will automatically be asked to enter a password before viewing it.

Password PDFs is a useful feature for people who work with sensitive data. Adding protection to documents is not a fix-all, but it can save you from some problems connected to the spread of information. 

The whole process is straightforward and accessible from any device connected to the internet. You can quickly increase the security of files using a browser on your desktop, iPhone, and iPad. 

Unlocking your document (when you decide that it no longer needs a key) is also available on 

BackgroundHow to Password PDF on iPhone

How to Password PDF on Android

If you have an Android tablet or smartphone it is really easy to password your PDFs. The procedure is similar for all smartphones, tablets, and desktops. Really, all you need is a web browser and a connection to the internet. Lock PDFs on Android with AltoPDF to get quality protection:

  1. Open 
  2. Upload a file that needs to be secured. 
  3. Create a secure password. 
  4. Select Password PDF Now!. 
  5. Click Download Now to save the file and send it via email or transfer it to a flash drive. 
  6. Try another secure way to work with PDFs. Discover new opportunities with pdfFiller and guard all your data with the latest security features. 

Our systems include the best encryption features by default. Your information can’t get stolen while being transferred. Moreover, nobody will be able to steal it because all files are immediately deleted from all servers after you exit the Alto page.

You can unlock your documents later with’s services. Anybody who knows the password can unlock the PDF at any time, so you should pay attention to who you give the password to. 

BackgroundHow to Password PDF on Android


How do I encrypt a PDF to email?

If you need to send an important document via email, it has to be encrypted in advance. In order to do it, open AltoPasswordPDF, create a suitable password for your document and save the changes. After that, you can be sure that the information the file contains will be available only to people who you gave the PDF password to.