weflip is part of the Gocompare.com group. It does switch you automatically, so is more advanced than Comparethemarket’s Energy Check. However, It only switches to tariffs that pay them a commission, which tend to be the more expensive tariffs.
80% of the time, the cheapest deal was not shown. Hidden within the website the best deal was available, but as shown through Flipper's research, 97% of people can't find it.
45% of the time, the cheapest deal was not shown. Since free auto-switchers make money through commissions from suppliers they do not offer the best deal to their customers.