Vernazza, like rest of Italy, is generally considered to be very safe for solo female travelers. Crime rate is relatively low and people are known to be friendly and helpful. As a solo traveler, you can comfortably explore the quaint streets, enjoy the local food, and hike the Cinque Terre trails even on your own. However, as in any travel scenario, it is recommended to take basic precautions such as keeping your belongings secure and staying aware of your surroundings.