Detailed Answer
The official Guinness World Record for fastest typing on an alphanumeric keyboard is held by Barbara Blackburn (USA), who achieved 212 WPM sustained over 50 minutes in 2005, and peak speeds of 216 WPM on a Dvorak keyboard. However, using modern electronic tests and burst speeds, some competitive typists have claimed higher. On 1-minute tests, Sean Wrona reached 256 WPM (Typeracer, 2010). On 10FastFingers, 'Vipertv' scored 232 WPM. On Monkeytype, 'Mythical' reached 305 WPM in a 15-second test (but burst speeds aren't official records). For standard 5-minute tests, anything above 150 WPM is world-class.