If you'd like to try out what we're working on in Cypress, you can enable beta features for your project by turning on the experimental features you'd like to try.


You can pass the Cypress configuration options below to enable or disable experiments. See our Configuration Guide on how to pass configuration to Cypress.

experimentalFetchPolyfillfalseAutomatically replaces window.fetch with a polyfill that Cypress can spy on and stub. Note: experimentalFetchPolyfill has been deprecated in Cypress 6.0.0 and will be removed in a future release. Consider using cy.intercept() to intercept fetch requests instead.
experimentalInteractiveRunEventsfalseAllows listening to the before:run, after:run, before:spec, and after:spec events in the setupNodeEvents function during interactive mode.
experimentalModifyObstructiveThirdPartyCodefalseWhether Cypress will search for and replace obstructive code in third party .js or .html files. NOTE: Setting this flag removes Subresource Integrity (SRI).
experimentalSourceRewritingfalseEnables AST-based JS/HTML rewriting. This may fix issues caused by the existing regex-based JS/HTML replacement algorithm. See #5273 for details.
experimentalWebKitSupportfalseEnable experimental support for running tests in WebKit. When set, installs of playwright-webkit will be detected and available in Cypress. See Launching Browsers for more information.

Testing Type-Specific Experiments

You can provide configuration options for either E2E or Component Testing by creating e2e and component objects inside your Cypress configuration.

End-to-End Testing

These experiments are available to be specified inside the e2e configuration object:

experimentalSessionAndOriginfalseEnables cross-origin and improved session support, including the cy.origin() and cy.session() commands. This enables testIsolation=strict by default.
experimentalStudiofalseGenerate and save commands directly to your test suite by interacting with your app as an end user would.

Component Testing

These experiments are available to be specified inside the component configuration object:

experimentalSingleTabRunModefalseRun all specs in a single tab, instead of creating a new tab per spec. This can improve run mode performance, but can impact spec isolation and reliability on large test suites.


10.8.0Added experimentalWebKitSupport.
10.6.0Added support for experimentalSingleTabRunMode.
10.4.0Added support for experimentalModifyObstructiveThirdPartyCode.
9.6.0Added support for experimentalSessionAndOrigin and removed experimentalSessionSupport.
8.2.0Added support for experimentalSessionSupport.
7.1.0Added support for experimentalInteractiveRunEvents.
7.0.0Removed experimentalComponentTesting and made it the default behavior.
6.7.0Removed experimentalRunEvents and made it the default behavior.
6.3.0Added support for experimentalStudio.
6.2.0Added support for experimentalRunEvents.
6.0.0Removed experimentalNetworkStubbing and made it the default behavior when using cy.intercept().
6.0.0Deprecated experimentalFetchPolyfill.
5.2.0Removed experimentalShadowDomSupport and made it the default behavior.
5.1.0Added support for experimentalNetworkStubbing.
5.0.0Removed experimentalGetCookiesSameSite and made it the default behavior.
4.9.0Added support for experimentalFetchPolyfill.
4.8.0Added support for experimentalShadowDomSupport.
4.6.0Added support for experimentalSourceRewriting.
4.5.0Added support for experimentalComponentTesting.
4.3.0Added support for experimentalGetCookiesSameSite.