Redis
FreemiumThe in-memory data platform for caching, real-time apps, and AI.
Published 29 May 2026 · Last updated 27 September 2026
Scores
Popularity3/5
Widely used as a cache and message broker; often a background dependency in production stacks.
Learning Curve2/5
Simple key-value command set; minimal configuration required to get started.
Flexibility4/5
Multiple data structures; Lua scripting; Redis Modules extend core functionality significantly.
Performance5/5
In-memory with sub-millisecond read and write; purpose-built for high-throughput caching.
Portability4/5
Key-value commands are standard; many Redis-compatible alternatives exist.
About Redis
Redis is an in-memory data store first released in 2009 and used as a cache, session store, message broker, and primary database for data that needs sub-millisecond reads and writes. Keeping the working set in RAM is what makes it the default choice for caching, rate limiting, leaderboards, and real-time counters.
Beyond key-value pairs, Redis offers a rich set of data structures: strings, hashes, lists, sets, sorted sets, bitmaps, HyperLogLogs, geospatial indexes, and streams for append-only messaging. Since Redis 8, the capabilities once shipped separately as Redis Stack (search and vector search, JSON documents, time series, and probabilistic structures) are built into the core distribution, so one server covers vector similarity search for AI applications as well as classic caching.
Persistence comes from RDB snapshots and AOF logging, Redis Sentinel adds automatic failover, and Redis Cluster shards data across nodes. Licensing changed in 2024, when Redis moved from BSD to the source-available RSALv2 and SSPLv1 licenses; Redis 8 added AGPLv3 as a third option, restoring an OSI-approved open-source license. The Linux Foundation's Valkey fork continues from the last BSD-licensed release.
Redis runs self-hosted from official packages and Docker images, as Redis Cloud (a managed service with a free tier and hourly-billed Essentials and Pro plans), or as Redis Software for self-managed enterprise deployments. The major cloud providers also sell Redis-compatible managed caches.
Key Features
- In-memory storage for sub-millisecond latency
- Rich data structures: strings, hashes, lists, sets, sorted sets
- Built-in replication with Redis Sentinel for high availability
- Pub/sub messaging with streams support
- TTL-based key expiration for automatic cache invalidation
- Persistence options: RDB snapshots and AOF logging
- Horizontal scaling with Redis Cluster
- Search, vector search, JSON, and time series built in since Redis 8
Pros
- Sub-millisecond reads and writes from memory
- Sorted sets, streams, and hashes cover leaderboards, queues, and rate limiting without extra services
- One server handles caching, pub/sub, and vector search
- Client libraries for virtually every language and framework
- Robust clustering and replication options
- Small command set that is quick to learn
Cons
- Dataset size is bounded by RAM, which gets expensive for large datasets
- Data loss risk if persistence is not configured
- MULTI/EXEC transactions do not roll back on errors, so it is not a fit for strict ACID workloads
- Limited querying compared to relational databases
- Cluster management can be complex
- No longer permissively licensed: AGPLv3, RSALv2, or SSPLv1 (Valkey is the BSD fork)
Redis Pricing
Freemium- · Self-hosted Redis 8 with search, JSON, and time series built in
- · AGPLv3, RSALv2, or SSPLv1 license
- · Community support
- · Up to 30 MB
- · Single database on shared infrastructure
- · Best-effort SLA and community support
- · Billed hourly from $0.007/hour, $5/month minimum
- · 250 MB to 100 GB
- · Single database
- · Up to 99.99% uptime SLA
- · Billed hourly with a $200/month minimum
- · Dedicated deployment with multiple databases
- · Active-Active multi-region, auto-tiering, private connectivity
- · Up to 99.999% uptime SLA
- · Self-managed enterprise
- · Active-Active replication
- · Contact for pricing
Tech Stacks with Redis
Advanced API (Go)
ProjectA high-performance API stack for advanced engineers. Go handles concurrency, PostgreSQL + Redis back the data layer, Prometheus + Grafana provide observability, and Kubernetes can orchestrate containers as an optional addition.
n8n Self-Hosted
InfrastructureSelf-host n8n on your own VPS, cloud instance, or hardware for complete data ownership and no per-execution pricing. Docker keeps the deployment reproducible on any host; PostgreSQL, SQLite, or managed Neon can store workflows and execution history, and a reverse proxy you configure or a self-hosted PaaS handles routing and TLS.
PostHog Self-Hosted
InfrastructureSelf-host PostHog when product data must stay on infrastructure you control. The official Docker Compose deployment runs the PostHog services with PostgreSQL, ClickHouse, Kafka, and Redis on one large server, and it's built for modest volumes: PostHog recommends it below about 300,000 events a month.
Tools Related to Redis
Works well with Redis(3)
AWS ElastiCache provides managed Redis on AWS — a common caching and session layer for AWS-hosted backends; Auto Discovery handles cluster node changes transparently.
Azure Cache for Redis is a managed Redis service on Azure — a common caching and session layer for Azure-hosted backends, integrated with Azure Monitor and AAD authentication.
Redis is available as a managed service on Render, tightly coupled with Render web services and workers for caching and queue use cases.
Vendor
Redis
Website →Tags
Details
- Maintained
- Yes
- DB model
- Key-value
- Query language
- Custom
- Hosting
- Cloud & Self-hosted
- ACID compliant
- No
- Replication
- Yes
- GitHub stars
- 76.4k
- Stars updated
- 2026-09-23