The best kettles in the UK to save energy and speed up your cuppa, tested

We boiled litres of water to find the best electric kettles, from hard-water heroes to vintage-style, repairable and wifi-connected models• The best air fryers, tried and tested for crisp and crunchDespite the march of progress, the humble kettle remains a kitchen staple. It’s what we turn to in times of strife, when spirits are flagging, or to start our day. When a visitor calls, one of the first things we often do is put the kettle on.Many small appliances have evolved beyond their original form, but the kettle’s basic principles remain largely unchanged. Water goes in and heats until a thermostat switches it off; the water then pours out, and we enjoy a cuppa. However, the technology that goes into a kettle has been slowly improving: better insulation to keep water hotter for longer and…