Redis 8.4 Native Vector Search + LangCache Semantic Caching: 73% Cost Reduction, 96.9% Latency Cut on Cache Hits in Production LLM Workloads

Redis Blog·medium signal

Redis 8.4 (2026) ships native vector search, enabling semantic caching without external vector databases. Redis LangCache stores query embeddings alongside LLM responses and retrieves cached answers for semantically similar queries — latency drops from 1.67s to 0.052s per cache hit (96.9% reduction). Production hit rates range 60-85% in customer support and documentation workloads, reducing API calls by up to 68.8%. AWS reported 86% cost reduction while maintaining 91% accuracy.