You have three primary methods for installation. Choose based on your environment.
Once you have validated your upgrade path and secured a backup, you can install the firmware using either the graphical interface or the command line. Method 1: Installing via the GUI (Most Common) Log in to the FortiGate web UI. Navigate to > Firmware .
Currently, FortiOS 7.4.x is the recommended mature branch for most environments, with 7.4.8 being a specific version highlighted by the community. Always check the official Recommended Release document before making a final decision.
The system will prompt you with a warning about a reboot. Confirm the action by clicking . fortigate firmware download install
Navigate to > Firmware (on older versions, this may be under Dashboard > Status > Firmware Widget ).
Click and save the .out file to your local machine. Method B: Via the FortiGate GUI (Cloud Download)
Before discussing the how , let's discuss the why . Running outdated FortiOS firmware exposes your organization to several risks: You have three primary methods for installation
Downloading and installing firmware on a FortiGate firewall is a powerful but nerve-wracking process. While Fortinet provides robust tools and security-hardened images, the process is unforgiving of mistakes. It is not as "plug-and-play" as consumer router updates, but for enterprise-grade hardware, it offers the necessary controls.
Run diagnose debug config-error-log read to see if any lines of your old configuration failed to convert during the upgrade.
Log into your FortiGate GUI and navigate to System > Firmware (or Fabric Management in newer versions). Method 1: Installing via the GUI (Most Common)
To get the most stable, official firmware, you must use the Fortinet Support Portal. to the Support Portal. Navigate to Download > Firmware Images .
Click on your administrator username in the top-right corner. Select > Backup . Choose Local PC as the backup destination.
(Optional but recommended) Check and set a password to protect sensitive data like pre-shared keys. Click Backup to download the .conf file. Verify Your Support Contract