Softwr

Software · head to head

CloudWatch vs Prometheus

CloudWatch logo

CloudWatch

Software

AWS Monitoring and Observability

From
Free
Rated
-
Full reviewWebsite
Prometheus logo

Prometheus

Software

Open source monitoring and alerting toolkit for cloud native environments

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: CloudWatch the free tier covers 5 GB of log ingestion and 10 custom metrics a month, after which log ingestion is $0.50 per GB from 5 to 30 GB; Prometheus not suitable for per-request billing as collected data lacks 100% accuracy
  • They diverge on capability: CloudWatch covers Metrics collection, Prometheus covers Multi-dimensional Data Model.

Where they differ

Only the attributes on which CloudWatch and Prometheus actually diverge.

Attributes where CloudWatch and Prometheus differ
AttributeCloudWatchPrometheus
Pricing modelusage-basedopen-source
PlatformsWeb, ApiLinux, macOS, Windows
Founded20062015

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

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 CloudWatch

  • Metrics collection
  • Log aggregation
  • Dashboards
  • Alarms and notifications
  • API
  • Webhooks
  • REST
  • Web support

Only in Prometheus

  • Multi-dimensional Data Model
  • PromQL Query Language
  • Pull-based Collection
  • Service Discovery
  • Alerting Rules
  • Federation
  • Local Storage
  • Grafana

What people use each for

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

CloudWatch

  • Metrics and log collection for AWS workloadsnot Prometheus
  • Alarming on thresholds across AWS servicesnot Prometheus
  • Querying logs with Logs Insightsnot Prometheus
  • Live tailing logs during an incidentnot Prometheus
  • Distributed tracing alongside X-Raynot Prometheus

Prometheus

  • Cloud-native monitoring and alertingnot CloudWatch
  • Time-series metrics collectionnot CloudWatch
  • Infrastructure monitoringnot CloudWatch

Where each one falls short

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

CloudWatch

  • The free tier covers 5 GB of log ingestion and 10 custom metrics a month, after which log ingestion is $0.50 per GB from 5 to 30 GB
  • Custom metrics are $0.30 each for the first 10,000, so instrumenting broadly gets expensive before volume discounts apply
  • Each custom dashboard beyond the free three is $3 a month
  • Alarms are billed at $0.10 per alarm metric a month, with high-resolution alarms costing more
  • Log storage beyond the free 5 GB is $0.03 per GB per month on top of the ingestion charge

Prometheus

  • Not suitable for per-request billing as collected data lacks 100% accuracy
  • Hard limit on scrape body size; large responses cause scrape failure
  • Per-scrape sample limit enforced; exceeding limit marks targets as failed
  • Not designed for long-term durable storage; optimised for metrics collection

Pricing, plan by plan

CloudWatch

Free
  • FreeFree
    • Metrics collection
    • Log aggregation
    • Dashboards

Prometheus

Free

No published plan breakdown. See the Prometheus review.

Which should you pick?

Choose CloudWatch if

  • You need metrics collection.
  • You want to start without paying.
  • You work on Web, Api.
  • You also want log aggregation.
CloudWatch review

Choose Prometheus if

  • You need multi-dimensional data model.
  • You want to start without paying.
  • You work on Linux, macOS, Windows.
  • You also want promql query language.
Prometheus review

Questions people ask

Is CloudWatch or Prometheus better?
Neither clearly leads. CloudWatch starts at Free and Prometheus at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, CloudWatch or Prometheus?
CloudWatch starts at Free and Prometheus at Free.
Does CloudWatch or Prometheus run on more platforms?
CloudWatch runs on Web, Api. Prometheus runs on Linux, macOS, Windows.
Can I use CloudWatch for free?
Both have a free tier, so you can try either at no cost before committing.
What is CloudWatch best used for?
CloudWatch is most often used for metrics and log collection for aws workloads, alarming on thresholds across aws services, querying logs with logs insights, live tailing logs during an incident. Of those, metrics and log collection for aws workloads and alarming on thresholds across aws services are not what Prometheus is typically brought in for.
What can CloudWatch do that Prometheus cannot?
CloudWatch covers Metrics collection, Log aggregation, Dashboards, Alarms and notifications. Prometheus covers Multi-dimensional Data Model, PromQL Query Language, Pull-based Collection, Service Discovery.
ShareXLinkedInRedditWhatsAppEmail

Related pages

More on CloudWatch

More on Prometheus

Keep looking

Other head to heads