You can use a Private Browsing: *[https://support.mozilla.org/en-US/kb/private-browsing-browse-web-without-saving-info Private Browsing - Browse the web without saving information about the sites you visit] An addon to use Private Tab: *[https://addons.mozilla.org/pt-br/firefox/addon/private-tab/ Private Tab] You also can customize you Privacy settings: *[https://support.mozilla.org/en-US/kb/settings-privacy-browsing-history-do-not-track Settings for privacy, browsing history and do-not-track] Also: *[https://support.mozilla.org/en-US/kb/block-websites-storing-site-preferences Block websites from storing site preferences or login status in Firefox]

See: *Tools > Options > Privacy > Firefox will: "Use custom settings for history": "Remember search and form history" *https://support.mozilla.org/kb/Form+autocomplete