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Cloud · head to head

Thanos vs Caddy

Thanos logo

Thanos

Cloud

Highly available Prometheus with long-term object storage

From
Free
Rated
-
Full reviewWebsite
Caddy logo

Caddy

Cloud

Web server with automatic HTTPS by default

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Thanos several components — sidecar, store, querier, compactor, ruler — each with its own configuration and failure modes; Caddy smaller ecosystem than Nginx, so third-party guides and modules are fewer
  • They diverge on capability: Thanos covers Global query, Caddy covers Automatic HTTPS.

Where they differ

Only the attributes on which Thanos and Caddy actually diverge.

Attributes where Thanos and Caddy differ
AttributeThanosCaddy
PlatformsKubernetes, Linux, DockerLinux, macOS, Windows, Docker

Identical on both: starting price (Free), pricing model (Open source, no licence fee), free tier (Yes), user rating (Not yet rated), category (Cloud).

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 Thanos

  • Global query
  • Object storage retention
  • Deduplication
  • Downsampling

Only in Caddy

  • Automatic HTTPS
  • Caddyfile
  • Reverse proxy
  • Single binary

What people use each for

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

Thanos

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

Caddy

  • Sites and services where expired certificates have caused outages beforenot Thanos
  • Small deployments where Nginx configuration is more effort than the problem warrantsnot Thanos
  • Reverse proxying internal services with TLS without a certificate workflownot Thanos

Where each one falls short

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

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

Caddy

  • Smaller ecosystem than Nginx, so third-party guides and modules are fewer
  • Adding plugins means rebuilding the binary rather than loading a module
  • Under very high throughput Nginx generally still benchmarks ahead
  • Automatic certificate issuance needs outbound internet access, which complicates air-gapped deployments

Pricing, plan by plan

Thanos

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

Caddy

Free
  • CaddyFree
    • Full functionality
    • Commercial use permitted
    • Community support

Which should you pick?

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

Choose Caddy if

  • You need automatic https.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, Docker.
  • You also want caddyfile.
Caddy review

Questions people ask

Is Thanos or Caddy better?
Neither clearly leads. Thanos starts at Free and Caddy at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Thanos or Caddy?
Thanos starts at Free and Caddy at Free.
Does Thanos or Caddy run on more platforms?
Thanos runs on Kubernetes, Linux, Docker. Caddy runs on Linux, macOS, Windows, Docker.
Can I use Thanos for free?
Both have a free tier, so you can try either at no cost before committing.
What is Thanos best used for?
Thanos is most often used for querying metrics across many clusters or regions from one place, retaining metrics for years without local disk growth, removing the gap that appears when a single prometheus instance restarts. Of those, querying metrics across many clusters or regions from one place and retaining metrics for years without local disk growth are not what Caddy is typically brought in for.
What can Thanos do that Caddy cannot?
Thanos covers Global query, Object storage retention, Deduplication, Downsampling. Caddy covers Automatic HTTPS, Caddyfile, Reverse proxy, Single binary.

Answered from the vendors’ own pages

Thanos: Is Thanos free?

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

Caddy: Is Caddy free?

Yes, open source under the Apache 2.0 licence, free for commercial use.

Thanos: Does Thanos replace Prometheus?

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

Caddy: What does automatic HTTPS mean?

Caddy obtains certificates from Let’s Encrypt or ZeroSSL on first request and renews them before expiry, with no cron job or configuration.

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.

Caddy: Caddy or Nginx?

Caddy is dramatically simpler to configure and removes certificate management. Nginx has the larger ecosystem and better peak throughput.

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