There are multiple ways to perform Tab key functionality. Using Actions Class, Using SendKeys() method & few other. Let us talk about them one by one.

1. Using function sendKeys(Keys.Tab).
WebElement inputField = driver.findElement(By.Locator("LocatorValue"));
inputField.sendKeys(Keys.TAB);
2. If you are using Java then you can use Java ROBOT class to perform keyboard actions.
Robot robot = new Robot(); // Simulate key Events robot.keyPress(keyEvent.VK_TAB); robot.keyRelease(keyEvent.VK_TAB);
3. You can use Ascii value in send key function like sendKeys(//0061); I am not sure the ASCII value of Tag it’s just an example.
4. Using Actions class. –
Basically, you need to have instance of Actions class and then call sendKeys with TAB as TAB key.
package learnAboutActionsClass;
import java.util.concurrent.TimeUnit;
import org.openqa.selenium.By;
import org.openqa.selenium.Keys;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.interactions.Actions;
public class TabKeyUsingActionsClass {
public static void main(String[] args) {
// TODO Auto-generated method stub
WebDriver driver = new FirefoxDriver();
driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
driver.manage().window().maximize();
driver.navigate().to("http://automationtalks.com/");
WebElement element = driver.findElement(By.xpath("//input[@class='search']"));
element.sendKeys("text to be searched");
Actions act = new Actions(driver);
act.sendKeys(Keys.TAB).build().perform();
act.sendKeys(Keys.RETURN).build().perform();
}
}
Hope This Helps !!!!