The toJSON() method of the Performance interface is a standard serializer: it returns a JSON representation of the performance object's properties. Syntax myPerf = performance.toJSON() Arguments None Return value myPerf A JSON object that is the serialization of the Performance object. Example var js; js = window.performance.toJSON(); console.log("json = " + JSON.stringify(js)); Specifications Specification Status Comment High Resolution Time Level 2The definition of 'toJSON() serializer' in that specification. Candidate Recommendation Defines toJson(). Browser compatibility Desktop Mobile Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit) toJSON() No support (Yes) 25.0 (25.0) ? No support No support Feature Android Android Webview Edge Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile Chrome for Android toJSON() No support No support (Yes) 25.0 (25.0) 1.2 (25.0) ? No support ? No support