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Databases · head to head

Memcached vs Preact

M

Memcached

Databases

Distributed memory object caching system

From
Free
Rated
-
Full reviewWebsite
Preact logo

Preact

Web Development

3kB alternative to React with the same modern API

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Memcached no persistence at all: restart a node and its cache is gone, which every design must assume; Preact compatibility through preact/compat is good but not total, and some React libraries break in ways that are hard to diagnose
  • They diverge on capability: Memcached covers In-memory key-value cache, Preact covers 3kB runtime.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Memcached and Preact actually diverge.

Attributes where Memcached and Preact differ
AttributeMemcachedPreact
Pricing modelOpen source, no licence fee; managed cloud billed separatelyOpen source, no licence fee
PlatformsLinux, macOS, Windows, Docker, Self-hostedWeb
CategoryDatabasesWeb Development

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Memcached

  • In-memory key-value cache
  • Multithreaded
  • Client-side sharding
  • Predictable memory use

Only in Preact

  • 3kB runtime
  • preact/compat
  • Same modern API
  • Fast rendering

What people use each for

The jobs each tool is most often brought in to do.

Memcached

  • Caching expensive database query results to cut loadnot Preact
  • Session storage where losing sessions on restart is acceptablenot Preact
  • Fronting an API whose responses are costly and change slowlynot Preact

Preact

  • Embedded widgets that load inside someone else’s page and must stay smallnot Memcached
  • Marketing and content sites where JavaScript payload affects Core Web Vitalsnot Memcached
  • Applications targeting low-bandwidth or low-powered devicesnot Memcached

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Memcached

  • No persistence at all: restart a node and its cache is gone, which every design must assume
  • No replication or failover, so losing a node loses that share of the cache
  • Only simple key-value, with none of the lists, sorted sets or streams Redis offers
  • Values are capped at 1MB by default, which surprises teams caching large documents

Preact

  • Compatibility through preact/compat is good but not total, and some React libraries break in ways that are hard to diagnose
  • Behavioural differences from React exist in edge cases, particularly around event handling
  • A much smaller community, so unusual problems have fewer existing answers than React

Pricing, plan by plan

Memcached

Free
  • MemcachedFree
    • Full functionality
    • Self-hosted
    • No usage limits

Preact

Free
  • PreactFree
    • Full library
    • Commercial use permitted
    • No usage limits

Which should you pick?

Choose Memcached if

  • You need in-memory key-value cache.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, Docker, Self-hosted.
  • You also want multithreaded.
Memcached review

Choose Preact if

  • You need 3kb runtime.
  • You want to start without paying.
  • You also want preact/compat.
Preact review

Questions people ask

Is Memcached or Preact better?
Neither clearly leads. Memcached starts at Free and Preact at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Memcached or Preact?
Memcached starts at Free and Preact at Free.
Does Memcached or Preact run on more platforms?
Memcached runs on Linux, macOS, Windows, Docker, Self-hosted. Preact runs on Web.
Can I use Memcached for free?
Both have a free tier, so you can try either at no cost before committing.
What is Memcached best used for?
Memcached is most often used for caching expensive database query results to cut load, session storage where losing sessions on restart is acceptable, fronting an api whose responses are costly and change slowly. Of those, caching expensive database query results to cut load and session storage where losing sessions on restart is acceptable are not what Preact is typically brought in for.
What can Memcached do that Preact cannot?
Memcached covers In-memory key-value cache, Multithreaded, Client-side sharding, Predictable memory use. Preact covers 3kB runtime, preact/compat, Same modern API, Fast rendering.

Answered from the vendors’ own pages

Memcached: Is Memcached free?

Yes, open source with no licence fee.

Preact: Is Preact free?

Yes, open source under the MIT licence.

Memcached: Memcached or Redis?

Memcached is a pure cache: simpler, multithreaded and very predictable. Redis adds persistence, replication and rich data structures, which is why it is the default choice unless you specifically want a cache and nothing more.

Preact: Can I use React libraries with Preact?

Most, through the preact/compat layer. Compatibility is good but not complete, so libraries relying on React internals can break.

Memcached: Does Memcached persist data?

No. Everything is in memory and lost on restart, by design.

Preact: Why choose Preact over React?

Bundle size, almost always. If payload is not a binding constraint, React’s ecosystem is usually the better trade.

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