This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The lineNumber read-only property of the SecurityPolicyViolationEvent interface is the line number in the document or worker at which the violation occurred.


let lineNumber = violationEventInstance.lineNumber;


A number representing the line number at which the violation occurred.


document.addEventListener("securitypolicyviolation", (e) => {


Specification Status Comment
Content Security Policy Level 3
The definition of 'lineNumber' in that specification.
Working Draft Initial definition

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support Yes15591 No Yes Yes
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes Yes Yes591 Yes Yes Yes

1. From version 59: this feature is behind the security.csp.enable_violation_events preference (needs to be set to true). To change preferences in Firefox, visit about:config.

See also

Document Tags and Contributors

Contributors to this page: fscholz, chrisdavidmills
Last updated by: fscholz,