No.1 Free Firewall that finds threats and protect your PC

Comodo Firewall

Comodo Firewall

  -  5.4 MB  -  Freeware
  • Latest Version

    Comodo Firewall LATEST

  • Review by

    Michael Reynolds

  • Operating System

    Windows XP / Vista / Windows 7 / Windows 8 / Windows 10

  • User Rating

    Click to vote
  • Author / Product

    Comodo Group, Inc / External Link

  • Filename


Comodo's Free Firewall is your first layer of defense against viruses, worms, Trojans, hackers, and all Internet threats. Comodo's Firewall uses Default Deny Protection to prevent threats from occurring, rather than just detecting them when it's already too late.

Whenever an unknown piece of software is introduced to your system, the software cross-references it with a white-list of over 15 million trusted files and applications. If the file asking for access is on the list, the product can be sure it's safe for your computer to allow it to execute. If not, the tool will alert you that a possibly malicious file is trying to enter your PC.

The latest version sees a major leap forward in security and usability with the addition of cloud-based scanning and behavior analysis of unrecognized files - making Comodo Free Firewall unbeatable at detecting zero-day attacks. Under default settings, unknown and untrusted files are automatically scanned by cloud-based virus scanners then, while the file undergoes behavior analysis on a cloud server, it is run in a virtual environment (sandbox) on your local machine so that it cannot modify or affect data on your 'real' system. This ground-breaking method of protecting your PC means that only trusted applications are allowed to run.

Malware and untrusted files get nowhere near anything important AND you get to use your computer without interruption from nagging alerts. The software also boasts a powerful packet filtering firewall that helps you securely connect to the internet while blocking hackers from making incoming connections. It's easy to use and features an attractive interface that lets even beginners change settings to their liking.

The app comes with automatic updates and is the winner of the prestigious Editor's Choice award. Download it now and find out why prevention-based protection is the security technology of the future. Comodo Firewall for Windows is completely free for life.

5 top secrets why Comodo Firewall is different:
  • No complex configuration issues—perfect for amateur users
  • Quickly learns user behavior to deliver personalized protection
  • The user-friendly, attractive graphical interface
  • Lots of configuration options let techies configure things just as they like
  • DDP-based security keeps you informed and PCs safe

Free Version: It offers a free version that provides essential firewall protection. This can be a cost-effective solution for users on a budget.

Advanced Features: It includes advanced features such as intrusion detection, a sandbox for running suspicious applications, and customizable security rules, which can be useful for more experienced users.

Defense+ Technology: It uses its Defense+ technology to monitor and protect against potentially harmful applications and behavior. This can help identify and block malware and other threats.

Popularity: It has a reasonably large user base and a community of users who can provide support and share their experiences with the software.


Complex Configuration: It can be complex to configure, especially for users who are not experienced with firewall settings. Novice users may find it overwhelming.

Frequent Alerts: The default settings for the software can generate frequent pop-up alerts, which can be annoying for some users. However, these can be customized.

False Positives: Like many security tools, it may sometimes flag legitimate software or actions as suspicious, leading to false positives that disrupt normal usage.

Resource Intensive: It can be resource-intensive, particularly when using its more advanced features like the sandbox. This can impact system performance on older or less powerful computers.

User Interface: Some users have found the user interface of the program to be less intuitive and user-friendly compared to other firewall solutions.

Limited Support: While there is a user community that can provide assistance, Comodo's free version may not come with the same level of customer support as paid alternatives.

  • Comodo Firewall Screenshots

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    Comodo Firewall Screenshot 1
  • Comodo Firewall Screenshot 2
  • Comodo Firewall Screenshot 3
  • Comodo Firewall Screenshot 4
  • Comodo Firewall Screenshot 5

What's new in this version:

Comodo Firewall
- WSL 2 can not work when install CIS
- Solitaire can not run in sandbox
- System restore is restoring the registry issue
- cmdvirth can be stoped
- Support jumbo frames in fw
- Setting allow contained applications access to the clipboard does not work
- Fixed BSOD cased by cmderd on 32 bit OS

Comodo Firewall
- Change log not available for this version

Comodo Firewall
- Cis going to use reduced(light) database in default. Option added to updates section who wants to change database to regular one

- Cloud backup
- File submission problems

- Ipv4 loopback filtering remove problem
- No welcome screen at startup
- File list export still saves when canceled
- Issue in switching configurations
- Display wrong scan priority
- Desktop shortcut doesn't change after product upgraded to AV Advanced
- Translation of "Show Files" added
- Scan exclusions' translation added
- Malwares detected by manual scan removed instead of quarantined
- Web filtering doesn't accept valid string (e.g. "**")
- Tray icon status problem
- A file will be trusted which blocked by Viruscope and unblocked by user
- Product name is not updated in programs & features after activating new license key
- GUI window rendering bug
- False unrecognized files after running "Autorun Analyzer" from KillSwitch
- Wrong activation of warranty log
- Option "Go to folder" not available for Firewall and Hips rules
- Unrecognized non-executables file is not displayed in File List when it is opened by widget
- Network zones ip copy&paste issue
- Microsoft Silverlight alert in Run Virtual Desktop
- "Ignore once" action in web filtering will be logged

Comodo Firewall
- Migrated virtually all HTTP URLs to HTTPs.
- Folder Protection

- Upgrade over install doesn't work
- Https website filtering no longer works on Chrome 78
- Chrome crashes in Containment
- CIS creates error while unplugging USB
- Uninstallation & Installation failed
- Uninstallation of Comodo KillSwitch and Cleaning Essentials
- Freezes in Win10 build 1909/1903

Comodo Firewall
- Preventing unsigned DLLs from loading into CIS processes

- Due to popular demand added the ability to delete vendor rated by Comodo from Vendor List
- Added Czech language translations
- Add 'Windows Operating System' application to 'Windows System Applications' file group
- An alert is now shown that reboot is required if Clipboard Protection settings are changed

Comodo Firewall
- Added support of Chrome 76 for web-filtering

- Vulnerabilities reported by Tenable
- Crashes of cavwp.exe
- Please note, this release has been rolled out for new users
- We shall be rolling out updates for existing users over the next few weeks

Comodo Firewall
- This version will no longer updated on Windows XP and Windows Vista essentially making it the last supported version for those OSes. This is due to SHA1 deprecation. Future versions will also have a minimum system requirement on Windows 7 of Service Pack 1

- Dumps of cmdinstall appears after installation on Windows 7
- WMI errors are present in Windows Event Log
- Number of unrecognized files in the CIS widget is not recalculated after system reboot

Comodo Firewall
- Added ability to remove vendors rated by Comodo from Vendor List

- The issue where system becomes unresponsive with specific viruscope settings
- The issue where non PE files cannot be submitted by 'Submit Files'
- The issue where user rating was not applied in 'Vendor List' for vendor with name starts with space

Comodo Firewall

New for CIS 2019:
- Full Microsoft Redstone 5 Support
- Long path and case sensitive filenames support
- ELAM protection
- Extended Containment Rule "Created By" criteria with "Rating" attribute
- Extended sanbox rules with a vendor as a criteria
- Extended Vendor List with User rating
- "Heuristic Command-Line Analysis" and "Embedded Code Detection" for scanning and monitoring of auto-run entries
- Powershell_ise analysis support
- Option to automatically scan plugged-in devices
- Simplified installation
- First network zone detection is performed in background
- Widget is hidden by default but can be changed with an install setting available through the Options button
- Updated AV engine
- Overall performance and stability improvements
- WDSC integration performance and stability improvements

- Fixed extended OS boot time in some cases
- Fixed defect where full scan fails in some rare cases
- Unrecognized file does not launch in Sandbox second time after first viruscope detection
- Defect where 'Cmdagent.exe' consumes 40-50 % CPU constantly in some cases
- Rules for Website Filtering can't be added if all rules was deleted
- Uninstall of CIS Premium is periodically failed
- cmdagent.exe unexpectedly terminates in some rare cases
- Defect where cmdagent.exe unexpectedly terminates after install CIS with Secure Shopping on XP
- Sandboxed .bat scripts are displayed as cmd in active processes list
- Containment resetting process takes a long time in some cases
- Not able to play videos in Facebook inside sandboxed Opera
- BSOD when playing Freeridesgames games
- This release has be rolled out for new users. We shall be rolling out updates for existing users over the next few weeks