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Memcached

memcached.org

Free plan macOSLinuxAPISelf-hosted
Visit memcached.org
Spec score 7.9 #10 of 27 in Caching Software

What it is

Memcached is a free, self-hosted in-memory key-value cache for reducing database load in dynamic web applications. It keeps small chunks of arbitrary data, such as strings, objects, and results from database calls, API calls, or page rendering. Clients use key-based hashing to choose a server, while servers operate independently without synchronization or replication. Items can expire after a specified time, and the default eviction policy is least recently used (LRU). The project describes Memcached as a developer tool, not code acceleration software or database middleware. Its API is available for most popular languages, and downloads include a source tarball and installation instructions with package prerequisites for Debian/Ubuntu and Red Hat/CentOS. TLS authentication and encryption are supported in version 1.5.13 and later when built with TLS and used with a TLS-capable client. Optional extstore moves values to external storage while keeping keys and the hash table in memory; it needs version 1.6.0 or newer. The project began in 2003. It is free and self-hosted, with no hosted plan or price listed.

Spec sheet

Purpose
Memcached is a distributed in-memory key-value cache intended to speed up dynamic web applications by reducing database load.Read 30 Sep 2026 · memcached.org
Support
The project directs users to its Discord chat, documentation, and mailing list for questions, and points to Cache Forge for business support.Read 30 Sep 2026 · memcached.org
Founded
2003Read 28 Sep 2026 · memcached.org
Cached data
It stores small chunks of arbitrary data, such as strings and objects, including results from database calls, API calls, or page rendering.Read 30 Sep 2026 · memcached.org
Cluster model
Clients use a key-based hashing algorithm to select a server, while servers operate independently without synchronization or replication.Read 30 Sep 2026 · docs.memcached.org
Developer audience
The documentation describes Memcached as a developer tool and says it is not code acceleration software or database middleware.Read 30 Sep 2026 · docs.memcached.org
Expiration and eviction
Items can expire after a specified time, and the default eviction policy is least recently used (LRU).Read 30 Sep 2026 · docs.memcached.org
Flash storage
The optional extstore feature moves values to external storage while keeping keys and the hash table in memory, and requires Memcached 1.6.0 or newer.Read 30 Sep 2026 · docs.memcached.org
Flash storage limit
Extstore requires flash storage rather than rotational media, and a Memcached restart effectively empties its flash data.Read 30 Sep 2026 · docs.memcached.org
Installation
The downloads page provides a source tarball and installation instructions, including package prerequisites for Debian/Ubuntu and Red Hat/CentOS.Read 30 Sep 2026 · memcached.org
Item size limit
The use cases documentation cites a 1 MB item-size limit.Read 30 Sep 2026 · docs.memcached.org
Language support
The maker says its API is available for most popular languages.Read 30 Sep 2026 · memcached.org
Origin
Memcached was originally developed by Brad Fitzpatrick for LiveJournal in 2003.Read 30 Sep 2026 · memcached.org
Performance
The documentation says queries on slow machines should run well under 1 ms and high-end servers can serve millions of keys per second.Read 30 Sep 2026 · docs.memcached.org
SASL security
SASL can authenticate clients but does not encrypt communications, and the documentation says it is not suitable for use over the internet.Read 30 Sep 2026 · docs.memcached.org
TLS security
Memcached 1.5.13 and later supports authentication and encryption via TLS when built with TLS enabled and used with a TLS-capable client.Read 30 Sep 2026 · docs.memcached.org

Plans and prices

Memcached Free Free & open source Self-hosted software · no hosted plan or price listed Read 30 Sep 2026 · memcached.org

Every Memcached plan and price →

Strong points and limits

Strong points

  • Caches small strings, objects, and application results.
  • Supports expiration and least-recently-used eviction.
  • APIs are available for most popular languages.
  • TLS authentication and encryption are supported in qualifying setups.
  • Free and self-hosted.

Limits

  • Servers do not synchronize or replicate.
  • Cited item-size limit is 1 MB.
  • Extstore requires flash, not rotational media.
  • Restarting Memcached effectively empties extstore data.

Who it suits

It suits developers who need a self-hosted cache for database, API, or page-rendering results. Users should be comfortable installing and operating the software themselves.

Verdict

Memcached provides a focused cache for developers who can manage their own deployment. Independent servers and the cited 1 MB item limit are important constraints; there is no hosted plan or price listed.

Where Specifiction places it

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