Chrome:
Copy and paste this URL into your browser, and press Enter.
- chrome://settings/content/all?searchSubpage=timetabling.education
- click the trash can

Edge:
Copy and paste this URL into your browser, and press Enter.
- edge://settings/privacy/cookies/AllCookies?searchSubpage=timetabling.education
- click 'Remove all shown'

Firefox: 

Go to the top left and click the three little lines.  

Select Options. 

Left-hand side, click Privacy, and then click "Clear all current History".

From the dialogue box, select all items and click Clear Now.

Safari:

press ⌘ Command + R

If you would like to clear all the caches or parts of it, complete the following steps;

  1. In the top menu, choose Safari.

  2. Click Preferences.

  3. Choose the Advanced tab.

  4. Enable the Show Develop menu in the menu bar.

  5. Go to Develop in the menu bar.

  6. Choose Empty caches.