Also known as: Redis Community Edition, Redis Stack, Redis Enterprise.
At a glance
| Data model | Key-value with rich data structures; JSON documents and vector sets in Redis 8 |
| Query language | Redis commands; FT.SEARCH, FT.AGGREGATE and FT.HYBRID query syntax for the Query Engine |
| Consistency model | Redis Cluster does not guarantee strong consistency (asynchronous replication); Active-Active uses strong eventual consistency |
| Replication | Asynchronous primary-replica; Active-Active multi-primary in Redis Software and Redis Cloud |
| Partitioning or sharding | Redis Cluster: 16,384 hash slots spread across primaries |
| Transactions | MULTI/EXEC transactions and Lua scripts; in Redis Cluster all keys in one command, transaction or script must share a hash slot |
| Vector search | FLAT, HNSW, SVS-VAMANA indexes; KNN, range queries, metadata filters; FT.HYBRID for hybrid search |
| Deployment and cloud availability | Self-hosted, Redis Software, Redis Cloud on AWS, Google Cloud and Azure; Redis-compatible services from cloud providers |
| Licensing | 7.2 and earlier BSD-3-Clause; 7.4 RSALv2 or SSPLv1; 8.0+ RSALv2, SSPLv1 or AGPLv3 |
Redis suits teams that need very fast access to data that fits in memory: caches, sessions, rate limiting, leaderboards and streams, and, since Redis 8, vector and hybrid search in the same server. Check the licence history before redistributing it, and compare Valkey if you need a BSD-licensed engine; Redis Cloud has a free 30 MB plan and hourly paid plans.
Overview
Redis is a key-value data store that keeps data in memory and offers data structures such as strings, hashes, lists, sets, sorted sets and streams, with optional persistence to disk. Since Redis 8, the former Redis Stack components (JSON, time series, probabilistic types and the Redis Query Engine for secondary indexing, full-text and vector search) ship inside Redis Open Source, together with vector sets, a new data type for similarity search. The current stable line was 8.10.3 on 26 October 2026, with 8.12 in release candidate.
Redis Ltd. sells two commercial editions: Redis Cloud, a managed service on AWS, Google Cloud and Azure, and Redis Software, the self-managed enterprise product (formerly Redis Enterprise). Both add features such as Active-Active geo-distribution, which uses conflict-free replicated data types. Other providers offer Redis-compatible services; see managed Redis hosting for ElastiCache, Azure Managed Redis, Memorystore and Upstash.
Key features
- In-memory data structures: strings, hashes, lists, sets, sorted sets, streams, plus JSON, time series and probabilistic types in Redis 8
- Redis Query Engine: secondary indexes over hashes and JSON with full-text, tag, numeric, geo and vector fields (FT.CREATE, FT.SEARCH, FT.AGGREGATE)
- Vector indexes FLAT, HNSW and SVS-VAMANA (added in 8.2), with L2, inner product and cosine distance and FLOAT32, FLOAT16, BFLOAT16, INT8 and UINT8 vectors
- Hybrid search with FT.HYBRID (since 8.4): combines BM25 text scoring and vector similarity through RRF or linear fusion, with pre-filters
- Vector sets (since 8.0): an HNSW-based data type with VADD and VSIM commands and attribute filters
- Redis Cluster sharding across 16,384 hash slots with asynchronous replicas and automatic failover
- Active-Active multi-region databases (CRDT based) in Redis Software and Redis Cloud Pro
Integrations and ecosystem
Pros and cons
Pros
- Very wide client library support and a simple command model for caching, sessions and queues
- Vector, full-text and hybrid search in the same server as the operational data since Redis 8
- AGPLv3 option means Redis 8 is again available under an OSI-approved licence
- Managed Redis Cloud on all three major clouds, with a free 30 MB plan and hourly pricing
Cons
- Dataset size is bounded by memory unless you use a tiering feature such as Redis Flex
- Redis Cluster can lose acknowledged writes during failover, according to the Redis documentation
- Licence changed twice since 2024; AGPLv3, RSALv2 and SSPLv1 all carry obligations to review
- Some SVS-VAMANA compression optimisations are Intel-proprietary and not available in Redis Open Source
Pricing
Redis Open Source is free to run under its licences. Redis Cloud, listed on the Redis pricing page on 7 November 2026 in USD: Free (up to 30 MB, shared, single database); Essentials from 0.007 USD per hour (the page shows 5 USD per month), 250 MB to 100 GB, single database on shared infrastructure; Pro from 0.014 USD per hour with a 200 USD per month minimum, dedicated deployment, multiple databases, Active-Active and Redis Flex. Annual plans and Redis Software (self-managed) are sold through sales, with no published prices.
Pricing checked on the vendor's official page on 7 November 2026. Prices change; confirm before buying.
Who it is best for
Application teams that need low-latency caching, session, queue or real-time data and want vector or hybrid search close to that data without running a separate search engine.
Typical use cases
- Caching database query results and rendered pages in front of a primary database
- Session storage, rate limiting and leaderboards with sorted sets
- Job queues and event streams with Redis Streams
- Semantic caching and retrieval for RAG applications using vector search
- Real-time product search combining keyword and vector relevance with FT.HYBRID
Who should look elsewhere
- Systems of record that need strong consistency and relational constraints: see Redis vs PostgreSQL.
- Large document datasets that do not fit in memory: see Redis vs MongoDB.
Verdict
Redis remains a default choice for in-memory caching and real-time data, and Redis 8 makes it a credible vector and hybrid search engine for datasets that fit in memory. Weigh the licence history (or the BSD Valkey fork) and memory cost against the convenience of one server for cache and search.
Frequently asked questions
Is Redis open source?
Redis 8.0 and later can be used under AGPLv3, which is OSI-approved, or under RSALv2 or SSPLv1. Redis 7.4 was RSALv2 or SSPLv1 only, and 7.2 and earlier were BSD-3-Clause. Redis Software and Redis Cloud are commercial.
Can Redis be used as a vector database?
Yes. The Redis Query Engine indexes vectors stored in hashes or JSON with FLAT, HNSW or SVS-VAMANA indexes and supports KNN, range queries and metadata filters; FT.HYBRID (Redis 8.4+) adds hybrid text and vector search. Redis 8 also has vector sets, a separate HNSW-based data type.
How much does Redis Cloud cost?
On 7 November 2026 the Redis pricing page listed Free (30 MB), Essentials from 0.007 USD per hour (5 USD per month shown) for 250 MB to 100 GB, and Pro from 0.014 USD per hour with a 200 USD per month minimum. Prices are in USD and vary by cloud, region and size.
What is the difference between Redis Open Source, Redis Software and Redis Cloud?
Redis Open Source is the free server. Redis Software is the self-managed commercial product (formerly Redis Enterprise) with features such as Active-Active. Redis Cloud is the managed service run by Redis Ltd. on AWS, Google Cloud and Azure.
Sources
- Redis licences
- Redis pricing
- Redis is now available under AGPLv3 (1 May 2025)
- Redis vector search concepts
- FT.HYBRID command
- Redis vector sets
- Scale with Redis Cluster
- Redis releases on GitHub
Checked November 2026.
Listed in: NoSQL & Distributed Databases, Vector Databases & AI Search.
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