The method for typing an umlaut varies according to whether a Windows or Mac operating system is being used. On a Windows PC, the Alt key is held down while entering a four-digit code. Typing an umlaut on a Mac involves using a press and hold technique.
When using Windows to type an umlaut, the number lock must first be activated before typing the proper code on the numeric keypad. Certain keyboards without a number lock and a numeric keypad require the user to hold down the Function key while pressing and releasing the Num Lock key prior to entering the code.
Windows codes for uppercase characters are ?, 0196; ?, 0203; ?, 0207; ?, 0214; ?, 0220, and ?, 0159. The lowercase codes are ?, 0228; ?, 0235; ?, 0239; ?, 0246; ?, 0252, and ?, 0255.
On a Mac computer, press and hold any vowel on the keyboard to reveal its alternate options, and either type the number that appears under the umlaut or click on the desired character.
Similarly, umlauts are accessible on most mobile devices by pressing and holding. For Android and Apple devices, press and hold the vowel requiring an umlaut in order to display all of its alternate characters. Maintain contact with the touch screen while sliding the finger over to the desired character, and release.