Test performance.now() is at least as the timestamp the rAF callback. On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS Math.round(window.performance.now()) is >= Math.round(timestamp1) PASS Math.round(window.performance.now()) is >= Math.round(timestamp1) PASS Math.round(window.performance.now()) is >= Math.round(timestamp1) PASS Math.round(window.performance.now()) is >= Math.round(timestamp1) PASS Math.round(window.performance.now()) is >= Math.round(timestamp1) PASS Math.round(window.performance.now()) is >= Math.round(timestamp1) PASS Math.round(window.performance.now()) is >= Math.round(timestamp1) PASS Math.round(window.performance.now()) is >= Math.round(timestamp1) PASS Math.round(window.performance.now()) is >= Math.round(timestamp1) PASS Math.round(window.performance.now()) is >= Math.round(timestamp1) PASS successfullyParsed is true TEST COMPLETE