Case Study: Quizlet achieves sub-500ms search and real-time indexing with Elastic

Quizlet - Customer Case Study

Quizlet, one of the world’s leading online study tools with about 20 million monthly users and more than 4 billion indexed terms, needed to let students and teachers quickly find and create high-quality, user-generated study content. Their previous search (Sphinx) caused slow page loads—often 1–4 seconds—and required up to six hours for re-indexing, making fresh content unavailable when users needed it.

By adopting the Elastic Stack (Elasticsearch, Logstash, Kibana, and Application Search), Quizlet delivered real-time indexing and search-powered creation features like auto-suggest, language detection, and completion suggestions. The migration cut query response times to under 500 ms (about an 80% reduction), reduced database load by ~30%, absorbed large traffic spikes without issue, and centralized logging and monitoring to improve performance and uptime.

Quizlet

Thompson Paine

General Manager