USearch

USearch is a similarity search engine that indexes vectors and arbitrary objects for fast retrieval.

USearch is a minimalistic search engine designed to replace FAISS and Apache Lucene in the modern data stack. It implements the HNSW algorithm with better concurrency mechanisms, fewer memory allocations, and SIMD instructions to accelerate distance computations. The engine scales to billions of vectors per server and supports cross-language index sharing. It provides native bindings for C++, Python, JavaScript, Java, Rust, Go, C#, Swift, Objective-C, and Wolfram. Developers use it for image, video, molecule, DNA, RNA, and protein sequence search.

USearch at a glance

Best for: Software engineer
Runs on: open source, API
Pricing: Free
Released: February 2023
Category: AI coding tool
Website: unum.cloud

Key features

Implements the HNSW algorithm
Uses SIMD instructions for distance computations
Scales to billions of vectors per server
Provides native bindings for multiple languages
Supports cross-language index building and querying
Delivers high vector search performance

Use it for

Building image and video search systems
Performing molecule search in chemistry
Handling DNA, RNA, and protein sequences in biology

Alternatives to USearch

XERJ — It answers agent questions from an index instead of wasting tokens on context windows.
seekdb — Unifies relational, vector, and text data for production-grade AI agents.
zvec — It is a pure local, serverless vector database providing fast hybrid search.
TurboVec — Fits a 10 million document corpus in 4 GB of RAM and searches faster than FAISS.
SeekStorm — It delivers sub-millisecond lexical and vector search performance in Rust.
Orama — Runs in browsers, servers, and edge networks with zero dependencies.
Chroma — Object storage architecture with automatic query-aware data tiering and caching.
Meilisearch — It returns answers in less than 50 milliseconds with out-of-the-box relevancy.
Qdrant — Fast filtered vector search, self-hosted or in a managed cloud
LlamaIndex — It provides hosted APIs for parsing documents and extracting typed data with one API key.
Infinity — Achieves 0.1 milliseconds query latency on million-scale vector datasets.
Sgrep — Runs locally without accounts or hosted indexes using small CPU models.

All USearch alternatives