FAISS Flashcards

Looking for a quick way to understand FAISS and how it fits into modern AI search?
This page gives you a concise, practical overview with easy flashcards.
You’ll see what the library does, where it shines, and how teams use it in real projects.

In short, it’s an open-source toolkit for similarity search over dense vectors.
Engineers rely on it for recommendation engines, semantic lookup, and Retrieval-Augmented Generation (RAG).
Moreover, it supports several indexing strategies and scales from prototypes to huge datasets.

Before you dive into the cards, here’s a simple diagram that shows the typical flow from embeddings to nearest-neighbour results.
It helps connect the moving parts at a glance.

Vector search with FAISS: embeddings, index build, ANN query flow
Typical vector search flow: create embeddings, build an index, and retrieve nearest neighbours quickly.

Want to connect this library to an app? You can pair it with frameworks that manage documents, chunking, and prompting.
For example, see our guide on
LangChain vector stores for RAG.
In addition, the official repository provides clear examples and GPU notes.

Index types overview: Flat, IVF, HNSW, and Product Quantization
Common index choices help balance accuracy, speed, and memory.

Scroll down to the flashcards to study the essentials.
Then, explore the links at the end for deeper practice and examples.

🧠 FAISS Flashcards
🔍 What is FAISS?
FAISS (Facebook AI Similarity Search) is a library for fast similarity search and clustering of dense vectors.
⚡ What is it used for?
It powers vector search engines, recommendation systems, and retrieval in LLM workflows.
🧠 Which index types are available?
Flat (brute force), IVF, HNSW, and PQ enable approximate nearest neighbour search with trade-offs.
📚 How do you install it?
Install via pip (pip install faiss-cpu) or build with CUDA for GPU support.
⚙️ Does it support GPU?
Yes. The CUDA build accelerates indexing and search for large datasets.
💡 Key advantages?
High-speed nearest-neighbour lookups with efficient memory use, even at million-vector scale.
🔁 Can it work with LangChain?
Yes. It’s a supported vector store for RAG pipelines.
🧪 Does it support clustering?
It includes k-means clustering, which helps with embedding analysis and compression.
🧰 How does it compare to Pinecone?
This library is self-hosted and offers control. Pinecone is managed and reduces ops overhead.
🌐 Can it scale?
With GPU acceleration and smart indexes, teams handle billions of vectors efficiently.

To go further, experiment with small datasets first, then switch to approximate indexes for speed.
Next, evaluate recall vs latency and tune parameters to match your product goals.
Finally, profile GPU usage before scaling.

Read our tutorial on LangChain vector stores for end-to-end RAG setup.
For code samples and release notes, visit the
FAISS GitHub repository.