When contentEditable is set to "inherit", the attribute must be removed and element.contentEditable should return "inherit". On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". PASS document.getElementById("p").hasAttribute("contentEditable") is false PASS document.getElementById("p").contentEditable is "inherit" PASS document.getElementById("p").isContentEditable is false FIXME: setContentEditable with true/false/inherit string is not working properly. https://bugs.webkit.org/show_bug.cgi?id=52058 PASS window.getComputedStyle(p, "").getPropertyValue("-webkit-user-modify") is "read-only" PASS successfullyParsed is true TEST COMPLETE