To get to the delete browsing history option in your Opera Web browser you have to open the Preference dialog box. Go to the "File" menu, and select "Preferences." Click "History" in the menu located in the left-side panel. Clicking on the "Empty now" button will delete all of your current Opera search history.
Rather than manually deleting your search history, you can also configure your Opera Web browser to automatically delete your accumulated search history every time you exit your browser. Open the Preference dialog box, go to History, check the box next to "Empty on exit" and save your settings.
Additionally, you may also want to delete your Opera browser cookies. Your cookies show a record of your browsing history. To delete your cookies, instead of selecting "History" in the Preferences dialog box, select "Cookies."