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Preact vs Thanos

Preact logo

Preact

Web Development

3kB alternative to React with the same modern API

From
Free
Rated
-
Full reviewWebsite
Thanos logo

Thanos

Cloud

Highly available Prometheus with long-term object storage

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Preact compatibility through preact/compat is good but not total, and some React libraries break in ways that are hard to diagnose; Thanos several components — sidecar, store, querier, compactor, ruler — each with its own configuration and failure modes
  • They diverge on capability: Preact covers 3kB runtime, Thanos covers Global query.
  • Prices and features above were last checked on 29 August 2026.

Where they differ

Only the attributes on which Preact and Thanos actually diverge.

Attributes where Preact and Thanos differ
AttributePreactThanos
PlatformsWebKubernetes, Linux, Docker
CategoryWeb DevelopmentCloud

Identical on both: starting price (Free), pricing model (Open source, no licence fee), 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 Preact

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

Only in Thanos

  • Global query
  • Object storage retention
  • Deduplication
  • Downsampling

What people use each for

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

Preact

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

Thanos

  • Querying metrics across many clusters or regions from one placenot Preact
  • Retaining metrics for years without local disk growthnot Preact
  • Removing the gap that appears when a single Prometheus instance restartsnot Preact

Where each one falls short

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

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

Thanos

  • Several components — sidecar, store, querier, compactor, ruler — each with its own configuration and failure modes
  • The compactor is a common source of operational trouble and must not run twice against the same bucket
  • Query latency over object storage is meaningfully higher than local Prometheus
  • Object storage costs and API request charges become real at high volume

Pricing, plan by plan

Preact

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

Thanos

Free
  • ThanosFree
    • Full functionality
    • No usage limits
    • Community support

Which should you pick?

Choose Preact if

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

Choose Thanos if

  • You need global query.
  • You want to start without paying.
  • You work on Kubernetes, Linux, Docker.
  • You also want object storage retention.
Thanos review

Questions people ask

Is Preact or Thanos better?
Neither clearly leads. Preact starts at Free and Thanos at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Preact or Thanos?
Preact starts at Free and Thanos at Free.
Does Preact or Thanos run on more platforms?
Preact runs on Web. Thanos runs on Kubernetes, Linux, Docker.
Can I use Preact for free?
Both have a free tier, so you can try either at no cost before committing.
What is Preact best used for?
Preact is most often used for embedded widgets that load inside someone else’s page and must stay small, marketing and content sites where javascript payload affects core web vitals, applications targeting low-bandwidth or low-powered devices. Of those, embedded widgets that load inside someone else’s page and must stay small and marketing and content sites where javascript payload affects core web vitals are not what Thanos is typically brought in for.
What can Preact do that Thanos cannot?
Preact covers 3kB runtime, preact/compat, Same modern API, Fast rendering. Thanos covers Global query, Object storage retention, Deduplication, Downsampling.

Answered from the vendors’ own pages

Preact: Is Preact free?

Yes, open source under the MIT licence.

Thanos: Is Thanos free?

Yes, open source and CNCF-incubating. Costs are the object storage it uses.

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.

Thanos: Does Thanos replace Prometheus?

No. It runs alongside existing Prometheus servers, adding global query, deduplication and long-term storage.

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.

Thanos: Thanos or VictoriaMetrics?

Thanos layers onto Prometheus using object storage and is the more established multi-cluster answer. VictoriaMetrics is a separate store aiming at lower resource use and fewer moving parts.

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