HNSW (Hierarchical Navigable Small World) is an efficient algorithm for approximate nearest neighbor (ANN) search, designed to handle large-scale, high-dimensional data. It builds a graph-based index where data points are nodes, and edges represent their proximity. The algorithm organizes the graph into hierarchical layers. The top layers have fewer nodes and represent coarse-grained views of the dataset, while the lower layers have denser connections and finer granularity. During a search, HNSW starts at the top layer and navigates down, finding the nearest neighbors quickly by skipping irrelevant nodes. HNSW is valued for its balance of speed and accuracy, making it suitable for real-time applications like recommendation systems, image retrieval, and natural language queries. It’s commonly integrated into vector databases for managing embeddings efficiently.
What is HNSW?

- Natural Language Processing (NLP) Advanced Guide
- Getting Started with Zilliz Cloud
- Advanced Techniques in Vector Database Management
- Optimizing Your RAG Applications: Strategies and Methods
- Vector Database 101: Everything You Need to Know
- All learn series →
Recommended AI Learn Series
VectorDB for GenAI Apps
Zilliz Cloud is a managed vector database perfect for building GenAI applications.
Try Zilliz Cloud for FreeKeep Reading
What is the future of data governance?
The future of data governance is likely to be centered around increased automation, enhanced security measures, and a gr
How do voice assistants use speech recognition?
Voice assistants use speech recognition technology to convert spoken language into text, which allows them to interpret
What is the maximum input length an LLM can handle?
The maximum input length an LLM can handle depends on its architecture and implementation. Most transformer-based LLMs a