Coolmuster PDF Locker â Free 1-Year License for Windows
Lock any PDF with a password, choose up to 256-bit AES encryption, and decide who can print, copy or edit it. Coolmuster normally sells a 1-year license for $15.95. Thanks to the Coolmuster giveaway, you can grab it free until 6 October 2026.
Windows 11 / 10 / 8 / 7
57 MB installer
Regular price: $15.95/year
⥠Quick Read (30 seconds)
- What you get: A free license code for Coolmuster PDF Locker, a $15.95 Windows tool (the price of its 1-year, 1-PC plan).
- What it does: Adds open and owner passwords to PDFs, encrypts them, and restricts printing, copying and editing, in batches.
- Whatâs new: Version 3.0.2 added 256-bit AES encryption, the strongest level the PDF format supports.
- Deadline: The giveaway runs from 28 September to 6 October 2026. After that, code
COOL-RBWN-GIGStakes 20% off. - How to claim: Get your code on Coolmusterâs giveaway page, then register the app. Full steps are in the giveaway section below.
Emailing a PDF is easy. Controlling what happens to it afterwards isnât. Salary slips, bank statements, contracts and ID scans all end up forwarded, printed or copied in ways you never intended. The fix is simple: lock the file with a password and decide what people can do with it.
Coolmuster PDF Locker does exactly that on your Windows PC. It adds a password to open the file, a separate password to protect its permissions, and lets you pick the encryption strength. You can protect one PDF or a whole folder in a single run, all offline. With this Coolmuster giveaway, the full version is free.
What Is Coolmuster PDF Locker?
Itâs a standalone PDF encryption tool from Coolmuster, the developer behind tools like PDF Creator Pro and Word to PDF Converter. You donât need Adobe Acrobat installed. Add your files, choose your security settings, and encrypt them in one click.
It uses the two passwords built into the PDF standard:
- User (open) password: Nobody can open the PDF without it. This is the one that actually keeps your content private.
- Owner (permissions) password: Controls what readers can do once the file is open, such as printing, copying text or editing. Only someone with this password can change those rules.
Whatâs new in version 3.0.2
Coolmuster released version 3.0.2 on 30 April 2026. According to its official changelog, the update:
- Added 256-bit AES password encryption, on top of the older 40-bit RC4, 128-bit RC4 and 128-bit AES options.
- Added support for newer PDF formats.
- Fixed crash issues.
If you tried an older version, this is a meaningful upgrade. Earlier builds topped out at 128-bit AES.
Key Features at a Glance
Which encryption level should you choose?
Higher is more secure, but very old PDF readers may not open the strongest levels. Hereâs a quick guide:
â ď¸ Know the limits before you lock
- Permissions alone arenât real security. If you only set an owner password, anyone can still open the file, and permission-removal tools can strip those restrictions. For private files, always set an open password too.
- Use a strong password. Encryption is only as good as the password. Use 12+ characters, and store it in a password manager.
- Forget it and itâs gone. Thereâs no âreset passwordâ for an encrypted PDF. Keep an unencrypted copy somewhere safe if you might need it later.
- Windows only. Thereâs no Mac version of PDF Locker.
How to Get Coolmuster PDF Locker for Free
The whole process takes about three minutes. One tip before you start: save the license code and the email address you used. You need both to register, and Coolmuster wonât show the code again.
Share this giveaway on any network. One click unlocks the download links and codes below.
A new tab opens to share this page. Come back here â your content unlocks automatically.
â° Missed the giveaway? Coolmusterâs 20% discount code COOL-RBWN-GIGS brings the 1-year license down from $15.95 to $12.76. Or try Secure-PDF Pro, which also adds digital signatures and watermarks.
How to Password-Protect a PDF with Coolmuster PDF Locker
- Add your PDFs: Import one file or a batch, or drag and drop them into the main window.
- Set the open password: Enable the user password and type a strong password.
- Set the owner password: Enter a different password to protect the permission settings.
- Pick encryption: Choose 256-bit AES unless you need to support very old readers.
- Choose permissions: Allow or block printing, copying, editing, comments and form filling.
- Encrypt: Choose an output folder and start the process. The protected copies are saved there.
Who Should Grab This (and Who Can Skip It)
đ Good fit
- Anyone emailing payslips, invoices, statements or contracts
- Freelancers and small offices sharing client documents
- Teachers and creators who want to block copying or printing of e-books and notes
- Anyone who needs to lock dozens of PDFs at once
đ Can skip
- Mac and Linux users, as itâs Windows-only
- People who need digital signatures or watermarks too
- Anyone who already owns Adobe Acrobat Pro, which has this built in
Need a bigger toolbox? Our Ultimate Guide to PDF Tools for Windows covers editors, converters and security tools, including free options.
Our Verdict: Simple, Strong PDF Encryption
Coolmuster PDF Locker does one job well. It adds proper password protection to PDFs, handles whole batches at once, and, since version 3.0.2, supports 256-bit AES. It wonât sign or watermark documents, but if you just want your private PDFs locked down, itâs a free and easy win.
- New 256-bit AES encryption
- Batch encryption with drag and drop
- Fine-grained print, copy and edit controls
- Windows only
- No signatures or watermarks
- Fairly large 57 MB download
Frequently Asked Questions
Is Coolmuster PDF Locker free?
Itâs free to try, and a 1-year license normally costs $15.95. Through this giveaway, which runs until 6 October 2026, you can get a license code free.
Whatâs the difference between the open password and the owner password?
The open (user) password is needed to view the PDF at all. The owner password protects the permission settings, such as whether the file can be printed, copied or edited.
Which encryption level is the most secure?
256-bit AES, added in version 3.0.2. Itâs supported by Adobe Acrobat 9 and later and by all modern PDF readers.
Can I encrypt multiple PDFs at once?
Yes. Add several files or a folder, or drag them into the window, and PDF Locker applies the same password and settings to all of them.
Which Windows versions are supported?
Windows 11, 10, 8 and 7. Coolmuster lists a 750 MHz CPU, 512 MB RAM and 1 GB of free disk space as the minimum.
What is the latest version?
Version 3.0.2, released on 30 April 2026. It added 256-bit AES encryption, support for newer PDF formats and crash fixes.
The license code doesnât work. What now?
Make sure you enter the exact email address you used on the giveaway page, and paste the code instead of typing it. Codes can only be claimed while the giveaway is live. If it still fails, let us know in the comments.
đ Love free licenses? We post new ones every week. Browse the full collection in our Free Software Giveaways & License Keys hub, and bookmark it so you donât miss the next one.
Written by Ramakanth, Techno360. Version, pricing, giveaway dates and feature details are from Coolmusterâs official giveaway page, product page and changelog as of 28 September 2026 and may change.
