The confidence value tells you how “trustable” is the fact that one alternative is better than the other/s.
A high confidence value tells you that you can be certain that choosing the best alternative is the best option to improve your conversion rate. A low confidence value means that with the current results, even if one alternative has so far a higher conversion rate than another, this could still be due to random effects so you have to interpret the results with caution.
We recommend waiting for at least a 90% confidence value in order to be sure to choose the best alternative.
The more visitors you have and the bigger is the observed difference between the alternatives, the higher will be the confidence value.
See more information about running and monitoring experiments in our Getting Started Guide.