Safari

Step 1 : Click on Safari > Preferences:
Step 2 : Check the Advanced button > then check off Show Develop menu in the menu bar:
Step 3 : Click on the Develop button on the taskbar > Empty Caches


Google Chrome

Step 1 : Open Chrome and click on Customize and control Google Chrome button
Step 2 : Select More Tools > Clear Browsing Data
Step 3 : Choose the beginning of time option from the drop-down menu, then check the following
    Browsing history
    Download history
    Cookies and other site and plugin data
    Cached images and files
Step 4 : After that, click on the Clear browsing data button


Mozilla Firefox

1 : Click on the Firefox button on the task bar and select Preferences
2 : Click on the Advanced button > Network > then select the Clear Now button in the Cached Web Content section