How we saved 100 terabytes of memory by optimizing 1.1.1.1's DNS cache

2026-08-28

Optimizations in how cache entries are stored in the 1.1.1.1 DNS service led to more than a 50% reduction in memory usage per entry, resulting in the savings of roughly 100 terabytes of memory across the entire fleet. These changes also improved overall cache performance, with a 43% increase in insert throughput and a 19% decrease in lookup latency.