"On a failed integrity check, an error event is thrown. Developers wishing to provide a canonical fallback resource (e.g., a resource not served from a CDN, per

"On a failed integrity check, an error event is thrown. Developers wishing to provide a canonical fallback resource (e.g., a resource not served from a CDN, perhaps from a secondary, trusted, but slower source) can catch this error event and provide an appropriate handler to replace the failed resource with a different one." Source: https://w3c.github.io/webappsec/specs/subresourceintegrity/#handling-integrity-violations https://w3c.github.io/webappsec/specs/subresourceintegrity/#...