Browser caches are typically designed to maximize hit rates, with speed of individual operations a secondary consideration. However, in the case of mobile browsers this may result in degraded performance, as many mo- bile devices rely on low-speed flash devices which have been found to significantly impact application perfor- mance . æWe present log-structured cache, a novel cache design analogous to the log structured file systems . We take advantage of the characteristics of a cache to side-step the need for segment cleaning, the source of many per- formance troubles in log structured file systems . By optimizing for storage performance we are able to achieve a ten-fold performance improvement in cache operation (as measured on a Nexus 7 tablet), while in the worst case increasing miss rate by a relative factor of no more than 5%.