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Redis โ„ข VS memcached

Compare Redis VS memcached and see what are their differences

Redis logo Redis

Redis is an open source in-memory data structure project implementing a distributed, in-memory key-value database with optional durability.

memcached logo memcached

High-performance, distributed memory object caching system
  • Redis Landing page
    Landing page //
    2022-10-19

Redis is an open source (BSD licensed), in-memory data structure store, used as a database, cache and message broker. It supports data structures such as strings, hashes, lists, sets, sorted sets with range queries, bitmaps, hyperloglogs, geospatial indexes with radius queries and streams. Redis has built-in replication, Lua scripting, LRU eviction, transactions and different levels of on-disk persistence, and provides high availability via Redis Sentinel and automatic partitioning with Redis Cluster.

  • memcached Landing page
    Landing page //
    2023-07-23

Redis features and specs

  • Performance
    Redis is an in-memory data store, which allows it to provide extremely fast read and write operations. This makes it ideal for applications requiring real-time interactions.
  • Data Structures
    Redis offers a variety of data structures, such as strings, hashes, lists, sets, and sorted sets. This flexibility helps developers manage data more efficiently in different scenarios.
  • Scalability
    Redis supports horizontal scalability with features like clustering and partitioning, allowing for easy scaling as your application grows.
  • Persistence
    Though primarily an in-memory store, Redis provides options for data persistence, such as RDB snapshots and AOF logs, enabling data durability across reboots.
  • Pub/Sub Messaging
    Redis includes a built-in publish/subscribe messaging system, which can be used to implement real-time messaging and notifications.
  • Simple API
    Redis has a simple and intuitive API, which can speed up development time and make it easier to integrate Redis into various application stacks.
  • Atomic Operations
    Redis supports atomic operations on data structures, reducing the complexity of concurrent programming and making it easier to maintain data consistency.

Possible disadvantages of Redis

  • Memory Usage
    Being an in-memory data store, Redis can become expensive in terms of memory usage, especially when working with large datasets.
  • Data Persistence Limitations
    While Redis offers data persistence, it is not as robust as traditional databases. There can be data loss in certain configurations, such as when using asynchronous persistence methods.
  • Complexity in Scaling
    Although Redis supports clustering, setting up and managing a Redis cluster can be complex and may require significant DevOps expertise.
  • Single-threaded Nature
    Redis operates on a single-threaded event loop, which can become a bottleneck for certain workloads that could benefit from multi-threading.
  • Limited Query Capabilities
    Compared to traditional relational databases, Redis offers limited querying capabilities. Complex queries and joins are not supported natively.
  • License
    As of Redis 6 and higher, the Redis modules are under the Server Side Public License (SSPL), which may be restrictive for some use cases compared to more permissive open-source licenses.

memcached features and specs

  • High Performance
    Memcached is incredibly fast and efficient at caching data in memory, enabling quick data retrieval and reducing the load on databases. Its in-memory nature significantly reduces latency.
  • Scalability
    Memcached can be easily scaled horizontally by adding more nodes to the caching cluster. This allows it to handle increased loads and large datasets without performance degradation.
  • Simplicity
    Memcached has a simple design and API, making it easy to implement and use. Developers can quickly integrate it into their applications without a steep learning curve.
  • Open Source
    Memcached is free and open-source software, which means it can be used and modified without any licensing fees. This makes it a cost-effective solution for caching.
  • Language Agnostic
    Memcached supports multiple programming languages through various client libraries, making it versatile and suitable for use in diverse tech stacks.

Possible disadvantages of memcached

  • Data Volatility
    Memcached stores data in RAM, so all cached data is lost if the server is restarted or crashes. This makes it unsuitable for storing critical or persistent data.
  • Limited Data Types
    Memcached primarily supports simple key-value pairs. It lacks the rich data types and more complex structures supported by some other caching solutions like Redis.
  • No Persistence
    Memcached does not offer any data persistence features. It cannot save data to disk, so all information is ephemeral and will be lost on system reset.
  • Size Limitation
    Memcached has a memory limit for each instance, thus, large-scale applications may need to manage multiple instances and ensure data is properly distributed.
  • Security
    Memcached does not provide built-in security features such as authentication or encryption. This can be a concern in environments where data privacy and security are critical.

Analysis of memcached

Overall verdict

  • Memcached is a solid choice for applications that require distributed caching to improve scalability and performance. It's particularly beneficial for web applications handling high traffic and needing fast, efficient data retrieval.

Why this product is good

  • Memcached is considered good due to its high performance, simplicity, and effectiveness in enhancing the speed of dynamic web applications by alleviating database load. It operates by storing data in memory, which allows for quick retrieval of cached objects and reduces the need to frequently query the database. Its distributed architecture, open-source nature, and widespread language support make it a flexible and reliable choice for caching.

Recommended for

  • Web developers looking to improve the speed and scalability of applications.
  • Organizations needing a simple and effective caching solution to reduce database load.
  • Projects that demand quick deployment of a caching solution with support across multiple programming languages.

Redis videos

What is Redis? | Why and When to use Redis? | Tech Primers

More videos:

  • Review - Improve your Redis developer experience with RedisInsight, Redis Labs
  • Review - Redis Labs "Why NoSQL is a Safe Bet"
  • Review - Redis Enterprise Overview with Yiftach Shoolman - Redis Labs
  • Review - Redis system design | Distributed cache System design
  • Review - What is Redis and What Does It Do?
  • Review - Redis Sorted Sets Explained

memcached videos

Course Preview: Using Memcached and Varnish to Speed Up Your Linux Web App

Category Popularity

0-100% (relative to Redis and memcached)
Databases
80 80%
20% 20
NoSQL Databases
80 80%
20% 20
Key-Value Database
74 74%
26% 26
Relational Databases
100 100%
0% 0

User comments

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Reviews

These are some of the external sources and on-site user reviews we've used to compare Redis and memcached

Redis Reviews

Redis Alternative for App Performance | Gigaspaces
Redis offers a RESTful API for accessing data stored within its in-memory technology data structures. This API provides a simple and efficient way to interact with Redis, enabling developers to leverage its capabilities seamlessly in their applications. Developers also need to manage the Redis cached data lifecycle, itโ€™s the application responsibility to store the data &...
Are Free, Open-Source Message Queues Right For You?
A notable challenge with Redis Streams is that it doesn't natively support distributed, horizontal scaling. Also, while Redis is famous for its speed and simplicity, managing and scaling a Redis installation may be complex for some users, particularly for persistent data workloads.
Source: blog.iron.io
Redis vs. KeyDB vs. Dragonfly vs. Skytable | Hacker News
1. Redis: I'll start with Redis which I'd like to call the "original" key/value store (after memcached) because it is the oldest and most widely used of all. Being a long-time follower of Redis, I do know it's single-threaded (and uses io-threads since 6.0) and hence it achieves lesser throughput than the other stores listed above which are multi-threaded, at least to some...
Memcached vs Redis - More Different Than You Would Expect
Remember when I wrote about how Redis was using malloc to assign memory? I lied. While Redis did use malloc at some point, these days Redis actually uses jemalloc. The reason for this is that jemalloc, while having lower peak performance has lower memory fragmentation helping to solve the framented memory issues that Redis experiences.
Top 15 Kafka Alternatives Popular In 2021
Redis is a known, open-source, in-memory data structure store that offers different data structures like lists, strings, hashes, sets, bitmaps, streams, geospatial indexes, etc. It is best utilized as a cache, memory broker, and cache. It has optional durability and inbuilt replication potential. It offers a great deal of availability through Redis Sentinel and Redis Cluster.

memcached Reviews

Redis vs. KeyDB vs. Dragonfly vs. Skytable | Hacker News
Quick ask: I donรขย€ย™t see รขย€ยœsomeรขย€ย of the other offering out there like MemCachedรขย€ยฆ what was the criteria used to select these? I donรขย€ย™t see any source of how the test where run, specs of the systems, how the DB where set up, etc. Would be very valuable to have in order to attempt to re-validate these test on our own platform. I also came back and saw some of your updates...
Memcached vs Redis - More Different Than You Would Expect
So knowing how the difference between Redis and memcached in-memory usage, lets see what this means. Memcached slabs once assigned never change their size. This means it is possible to poison your memcached cluster and really waste memory. If you load your empty memcached cluster with lots of 1 MB items, then all of the slabs will be allocated to that size. Adding a 80 KB...
Redis vs. Memcached: In-Memory Data Storageย Systems
Memcached itself does not support distributed mode. You can only achieve the distributed storage of Memcached on the client side through distributed algorithms such as Consistent Hash. The figure below demonstrates the distributed storage implementation schema of Memcached. Before the client side sends data to the Memcached cluster, it first calculates the target node of the...
Source: medium.com
Why Redis beats Memcached for caching
Both Memcached and Redis are mature and hugely popular open source projects. Memcached was originally developed by Brad Fitzpatrick in 2003 for the LiveJournal website. Since then, Memcached has been rewritten in C (the original implementation was in Perl) and put in the public domain, where it has become a cornerstone of modern Web applications. Current development of...

Social recommendations and mentions

Based on our record, Redis should be more popular than memcached. It has been mentiond 226 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.

Redis mentions (226)

  • Hacktoberfest 2025 with Ghostfolio
    The software is fully written in TypeScript and organized as an Nx workspace, utilizing the latest framework releases. The backend is based on NestJS in combination with PostgreSQL as a database together with Prisma and Redis for caching. The frontend is developed with Angular. - Source: dev.to / 6 days ago
  • Redis Explained: What It Is, Why You Need It, and How to Install It the Easy Way
    Hereโ€™s the thing: sometimes itโ€™s not your databaseโ€™s fault. Whatโ€™s missing is a speed booster in your architecture: Redis. - Source: dev.to / 29 days ago
  • Real-Time Sync Alternatives: Vaultrice vs. localStorage, DIY, Firebase, Pusher
    This is the path of ultimate control. You spin up a Node.js server, add the socket.io library for WebSocket communication, and use a Redis instance to manage connection state and pub/sub messaging across multiple server instances. - Source: dev.to / about 1 month ago
  • Is Your Fraud Screening Process Ignoring Local Patterns?
    Your Database: This is your system's memory. It can be a fast in-memory store like Redis for temporary data (perfect for velocity checks) or a persistent relational database like PostgreSQL for long-term data (like blacklists). - Source: dev.to / about 1 month ago
  • Redis vs. Memcached: How to Choose Your NoSQL Champion
    Redis is also an in-memory system with exceptional performance. But unlike Memcached, Redis is known as a "data structure server." It doesn't just support simple key-value pairs; it offers a rich variety of complex data structures like Lists, Hashes, Sets, and Sorted Sets. - Source: dev.to / about 2 months ago
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memcached mentions (37)

  • Redis vs. Memcached: How to Choose Your NoSQL Champion
    Memcached has a single, focused goal: to be a high-performance, distributed, in-memory object caching system. It stores all data in RAM, which means reads and writes are incredibly fast. But its main weakness is just as clear: data is completely lost when the service restarts, as it offers no persistence. Its data model is a simple key-value store, limited to basic get, set, and delete operations. - Source: dev.to / about 2 months ago
  • MySQL Performance Tuning Techniques
    Memcached can help when lightning-fast performance is needed. These tools store frequently accessed data, such as session details, API responses, or product prices, in RAM. This reduces the laid on your primary database, so you can deliver microsecond response times. - Source: dev.to / 7 months ago
  • 10 Best Practices for API Rate Limiting in 2025
    In-memory tools like Redis or Memcached for fast Data retrieval. - Source: dev.to / 8 months ago
  • Outgrowing Postgres: Handling increased user concurrency
    A caching layer using popular in-memory databases like Redis or Memcached can go a long way in addressing Postgres connection overload issues by being able to handle a much larger concurrent request load. Adding a cache lets you serve frequent reads from memory instead, taking pressure off Postgres. - Source: dev.to / 8 months ago
  • API Caching: Techniques for Better Performance
    Memcached โ€” Free and well-known for its simplicity, Memcached is a distributed and powerful memory object caching system. It uses key-value pairs to store small data chunks from database calls, API calls, and page rendering. It is available on Windows. Strings are the only supported data type. Its client-server architecture distributes the cache logic, with half of the logic implemented on the server and the other... - Source: dev.to / 12 months ago
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What are some alternatives?

When comparing Redis and memcached, you can also consider the following products

MongoDB - MongoDB (from "humongous") is a scalable, high-performance NoSQL database.

Apache Cassandra - The Apache Cassandra database is the right choice when you need scalability and high availability without compromising performance.

ArangoDB - A distributed open-source database with a flexible data model for documents, graphs, and key-values.

CouchBase - Document-Oriented NoSQL Database

Aerospike - Aerospike is a high-performing NoSQL database supporting high transaction volumes with low latency.

PostgreSQL - PostgreSQL is a powerful, open source object-relational database system.