Your browser caches data in order to access it quicker the next time. While this speeds things up, it can also sometimes cause problems by presenting outdated information. Each browser has different steps to clear the cache. Here are the steps for the more popular browsers:
Internet Explorer
Click on the gear icon in the upper right. Hover your mouse over Safety, then click on Delete browsing history.... You only need to keep the top 2 checked, as shown in the following image. Once you have the appropriate checkboxes checked, click Delete.
Mozilla Firefox
Click on the menu, and go to Options. Click on the Advanced tab, and then click on the Network tab. Under Cached Web Content, click Clear Now.
Google Chrome (And Other Chromium-based Browsers)
These are browsers that use the Chromium engine, such as Google Chrome, SRWare Iron, Torch, etc. To clear the cache, click on the menu button in the upper right, and hover your mouse over Tools, then click on Clear browsing data.... The only one you need checked is Empty the cache (see the following image). You can just leave the dropdown box on the past hour, then click the Clear browsing data button.
Opera
Click on the menu button, hover your mouse over Settings, and click Clear Private Data.... By default, all but 3 are checked, but this is unnecessary. The only one you should check is Delete entire cache (see following image). Finally, click Delete.
