How to Download and Install ClamAV for Free

Is ClamAV Free?

ClamAV is not a commercial product with an upsell path. It is a standalone antivirus engine that anyone can download, inspect, modify, and redistribute under the GPL. This is why it remains widely used on Linux mail servers, in Docker containers, and by privacy-conscious users on Windows and macOS who want a free second-opinion scanner.

Current release: ClamAV 1.5.4 (7 August 2026). The previous stable branch, 1.4.6, is also available for users who need a longer-support line.

System Requirements

• Windows: Windows 7 or newer (32-bit and 64-bit). Official MSI installers and portable ZIP packages are available for x64, win32, and ARM64.
• macOS: macOS 10.13 (High Sierra) or newer. A universal PKG installer supports both Intel and Apple Silicon (x86_64 and arm64).
• Linux: Any modern 64-bit or 32-bit distribution. Official .deb and .rpm packages are provided, and ClamAV is also available from the package repositories of Debian, Ubuntu, Fedora, RHEL, Arch, and others.
• RAM: ~2 GB minimum; 3 GB+ recommended when running the ClamD daemon or scanning large mail queues.
• Storage: ~500 MB for the application, plus ~1–2 GB for the virus signature database.
• Network: Required for freshclam to download signature updates.

Latest version as of October 2026: 1.5.4. Check the official downloads page for the exact package for your architecture.

How to Install ClamAV on Linux

Linux is ClamAV's native platform. You have two options: install from your distribution's package manager (fastest), or use the official .deb/.rpm packages from clamav.net (newest version).

1. Option A — Distribution repository (recommended). Use your package manager:
   • Debian / Ubuntu / Linux Mint: sudo apt update && sudo apt install clamav clamav-daemon.
   • Fedora / RHEL / AlmaLinux: sudo dnf install clamav clamd clamav-update (enable EPEL first on RHEL/AlmaLinux).
   • Arch Linux: sudo pacman -S clamav.
2. Option B — Official .deb / .rpm from clamav.net. Download the package for your architecture from clamav.net/downloads. For RPM systems, install with sudo dnf install ~/Downloads/clamav-1.5.4.linux.x86_64.rpm. Note: official packages install to /usr/local and may require manual configuration of freshclam.conf and clamd.conf.
3. Update the signature database. Run sudo freshclam. On systemd distributions, the clamav-freshclam service may handle this automatically — check with systemctl status clamav-freshclam.
4. Start the daemon (optional). If you want on-access scanning or faster repeated scans, start ClamD: sudo systemctl enable --now clamav-daemon (Debian/Ubuntu) or the equivalent for your distribution.
5. Verify the installation. Run clamscan --version and freshclam --version to confirm both tools are working.

How to Install ClamAV on macOS

macOS users have two main routes: the official universal PKG installer or Homebrew.

1. Option A — Official PKG installer. Download clamav-1.5.4.macos.universal.pkg from clamav.net/downloads. Double-click the PKG and follow the installer prompts. It installs system-wide and works on both Intel and Apple Silicon.
2. Option B — Homebrew (recommended for CLI users). Run brew install clamav. Homebrew handles dependencies and makes future updates easier with brew upgrade clamav.
3. Configure freshclam. The Homebrew version ships with sample configuration files. Copy them into place:
   cp /opt/homebrew/etc/clamav/freshclam.conf.sample /opt/homebrew/etc/clamav/freshclam.conf
   Then edit the file to remove the Example line at the top (ClamAV refuses to run with the example config).
4. Update the database. Run freshclam to download the signature database.
5. Verify. Run clamscan --version.

Note: ClamAV on macOS is command-line only. For a graphical interface, consider ClamXAV (paid, uses the ClamAV engine) or run scans from Terminal.

How to Install ClamAV on Windows

Windows users get an MSI installer or a portable ZIP. The MSI is the standard choice.

1. Download the installer. Go to clamav.net/downloads and choose the MSI for your architecture:
   • x64 for most modern PCs (clamav-1.5.4.win.x64.msi).
   • win32 for 32-bit Windows (clamav-1.5.4.win.win32.msi).
   • arm64 for Windows on ARM (clamav-1.5.4.win.arm64.msi).
2. Run the MSI. Double-click the installer and follow the prompts. It installs ClamAV into Program Files and adds the ClamAV tools to your Start menu.
3. Open a command prompt as Administrator. ClamAV's command-line tools need elevated privileges for some operations.
4. Update the database. Navigate to the ClamAV installation directory (usually C:\Program Files\ClamAV) and run freshclam.exe. This downloads the signature database.
5. Verify. Run clamscan.exe --version.
6. No official GUI. ClamAV is command-line only on Windows. If you prefer a graphical interface, use a third-party front-end such as ClamWin; otherwise, the command-line tools are fully functional.

Getting Started

1. Understand what ClamAV is — and is not. ClamAV is an on-demand scanner. It does not provide real-time protection. Use it to scan suspicious files, downloads, or entire drives, but do not rely on it as your only antivirus on Windows or macOS.
2. Update before you scan. Always run freshclam before a scan, or ensure the clamav-freshclam service is running. An outdated database is the most common reason ClamAV "misses" malware.
3. Scan a file or folder. Use clamscan path/to/file for a single file. Add -r for recursive folder scans: clamscan -r ~/Downloads.
4. Scan an entire drive. On Windows: clamscan -r C:\Users\YourName\Downloads. On Linux/macOS: clamscan -r /home/username. Full-drive scans can take a long time — start with targeted folders.
5. Use ClamD for repeated scans. The ClamD daemon keeps the signature database loaded in memory, making subsequent scans much faster. Start it as a service and use clamdscan instead of clamscan.
6. Remove or quarantine infected files. Use --remove to delete infected files automatically (careful — this is irreversible) or --move=/path/to/quarantine to move them to a quarantine folder.

Useful Tips

• 🔄 Update daily. Run freshclam at least once a day, or let the clamav-freshclam service do it. New malware signatures are published frequently, and an outdated database is the biggest weakness of any signature-based scanner.
• 🖥️ Use ClamD for speed. If you scan often, start the ClamD daemon and use clamdscan instead of clamscan — it avoids reloading the signature database on every run.
• 📁 Start with targeted folders. Scan Downloads, Desktop, and email attachment folders first. Full-drive scans on large disks can take hours and are rarely necessary for routine checks.
• 🧪 Test with EICAR. The EICAR test file is a harmless string that all antivirus engines detect. Create a text file containing the EICAR string and scan it to confirm ClamAV is working before you rely on it for real threats.
• 🔒 Do not rely on ClamAV alone on Windows. Windows Defender provides real-time protection that ClamAV cannot. Use ClamAV as a second-opinion scanner, not a replacement.
• 📦 Docker users: ClamAV is available as an official Docker image (clamav/clamav). It is commonly used to scan uploaded files in web applications and CI pipelines.
• ⚙️ Configuration files matter. The official installers (especially .deb/.rpm from clamav.net and the macOS PKG) do not always include pre-configured freshclam.conf and clamd.conf. You may need to create them from the sample files and remove the Example line before ClamAV will run.
• 🧹 Quarantine, don't delete. Use --move instead of --remove when scanning important folders. Quarantining lets you restore a false positive; deleting is permanent.

ClamAV vs Windows Defender vs Commercial Antivirus

• ClamAV: Free, open source (GPLv2), cross-platform, and command-line driven. On-demand scanning only — no real-time protection. Best for Linux servers, mail gateways, Docker containers, and as a free second-opinion scanner on Windows and macOS. Detection of known malware is solid; detection of new/zero-day threats is weaker than commercial engines.
• Windows Defender (Microsoft Defender Antivirus): Built into Windows 10 and 11, free, with real-time protection, cloud-delivered intelligence, and behavioural analysis. It is the primary antivirus on Windows and is genuinely good. Best for everyday Windows users who want automatic, always-on protection with zero setup.
• Commercial antivirus (Norton, Bitdefender, Kaspersky, etc.): Paid subscriptions with real-time protection, firewalls, phishing protection, VPN bundles, and support. Higher detection rates for zero-day threats and better usability for non-technical users. Best for users who want a hands-off, fully managed security suite.

ClamAV does not compete with commercial antivirus on detection breadth or real-time protection — it was never designed to. Its value is in being free, open, scriptable, and cross-platform, which is why it dominates mail-server and container scanning. For desktop users, the practical setup is: Windows Defender as the primary real-time antivirus, ClamAV as a free on-demand second scanner.

Troubleshooting Common Issues

• ❌ "Database initialization error" or "Can't open file or directory." The signature database is missing or outdated. Run freshclam to download it. On Linux, ensure the clamav-freshclam service is running. On macOS/Homebrew, confirm you copied the sample config files and removed the Example line.
• 🔒 "Permission denied" when scanning. ClamAV needs read access to the files you scan. On Windows, run the command prompt as Administrator. On Linux/macOS, use sudo for system-wide scans, or ensure your user has read permissions on the target directory.
• 🐌 Scans are very slow. ClamAV is CPU-intensive, especially on first scans. Use clamdscan with the ClamD daemon for faster repeat scans. Exclude large archive files or virtual machine images if they are not relevant to your scan.
• 📡 freshclam fails with "Connection refused" or timeout. Check your network connection and firewall. ClamAV downloads from the official mirror network over HTTP/HTTPS. Some corporate networks block these domains — configure a proxy in freshclam.conf if needed.
• 🖥️ ClamAV won't launch on Windows. Ensure you are using the correct MSI for your architecture (x64 vs win32 vs arm64). If the installer fails, try the portable ZIP package and run clamscan.exe from the extracted folder.
• 🍎 macOS: "freshclam: command not found." The Homebrew-installed binaries may not be in your PATH. Check /opt/homebrew/bin (Apple Silicon) or /usr/local/bin (Intel). Add the appropriate directory to your shell's PATH.
• ⚠️ False positives. ClamAV's signature database is aggressive with some legitimate files (especially packed executables). If ClamAV flags a file you trust, submit it to the ClamAV false-positive tracker rather than deleting it immediately. Use --exclude or quarantine to isolate the file while you investigate.
• 🔄 Freshclam database update fails with "Your ClamAV installation is OUTDATED." A major version jump may be required. Download the latest installer from clamav.net and upgrade. On Linux, check whether your distribution's package is lagging behind and consider the official .deb/.rpm if you need the newest version.

Frequently Asked Questions

Does ClamAV have a graphical interface?

Can ClamAV replace Windows Defender?

Does ClamAV detect all malware?

How often should I update the virus database?

Does ClamAV send telemetry?

What is the current version of ClamAV?