Cloudflare’s Security Level uses the threat score (IP reputation) to decide whether to present a to the visitor. Once the visitor enters the correct challenge, they receive the appropriate website resources.
The threat score of a request has a value from 0 to 100, where 0 indicates low risk. Values above 10 may represent spammers or bots, and values above 40 identify bad actors on the Internet.
Security levels are based on the threat score (except Off and I’m Under Attack!). You can adjust the security level to challenge incoming requests based on the threat they pose.
The available security levels are the following:
|Threat score range
|Does not challenge IP addresses.
|Only challenges IP addresses with the worst reputation.
|Challenges only threatening visitors.
|Challenges both threatening and moderately threatening visitors.
|Challenges all visitors that exhibited threatening behavior within the last 14 days.
|I’m Under Attack!
|Only for use if your website is currently under a DDoS attack.
Selecting a higher Security Level value means that even requests with a lower risk (that is, with a low ) will be challenged. Selecting a lower Security Level value means that only requests posing a higher risk (that is, with a high threat score) will be challenged.
Customize security level
The default security level is Medium.
To update the security level for your entire zone:
- Log into the .
- Select your account and zone.
- Go to Security > Settings.
- For Security Level, select an option.
To set the security level more selectively, do one of the following:
- Configure it via a .
- Use the Threat Score as a Field criteria within . If you are using the Expression Editor, use the
To prevent bot IPs from attacking a website:
- A new website owner might set a Medium or High Security Level and lower to a value below 30 minutes to ensure that Cloudflare is constantly protecting the site.
- An experienced website administrator confident in their security settings might set Security Level to Essentially Off or Low while setting a higher for a week, month, or even year to provide a less obtrusive visitor experience.
You can also create to protect sensitive areas of your website — like comment form pages or login forms — using the in your rule expression. The flexibility of custom rules allows you to select the action to take (for example, challenge or block) and exclude specific IP addresses.