Harmful alcohol use is a major public health issue. In‐person treatment has been hindered by the restrictions necessary during the Covid‐19 pandemic. This study examined the effects of an at‐home smartphone‐based cognitive bias modification training in heavy drinkers. Experiment 1 tested the effect of a short 20–30‐min smartphone‐based approach‐avoidance training (AAT) on image‐induced craving at a 1‐day follow‐up. Sixty‐two participants consuming 14+ units of alcohol/week were allocated to either the training or waitlist group. Experiment 2 used an updated version of the same short AAT intervention with a sample of n = 107 participants who consumed 20+ units of alcohol/week. Training effects at 1‐week follow‐up were compared to an active control group. Experiment 1 showed a significant reduction in image‐induced craving for the training group at 1‐day follow‐up. Experiment 2 found that AUDIT weekly scores were significantly reduced at 1‐week follow‐up for the training group, all the while craving for soft drinks remained unchanged. Experiment 1 served as a first proof of concept for the efficacy of the new smartphone‐based AAT training, and experiment 2 suggested that training effects on problem alcohol use hold at 1‐week follow‐up.