Checkly vs Datadog

Checkly is a synthetic monitoring platform from Berlin built on the idea of monitoring as code. Engineering teams write API checks and browser checks in JavaScript or TypeScript, using Playwright for browser flows, keep them in the same repository as the application, and deploy them with the Checkly CLI or Terraform.

The same checks run in CI against preview deployments before a release and then continuously from global locations after it, so a broken login or checkout flow is caught by a test first and by monitoring second. Assertions, retries, alert channels such as Slack, PagerDuty and email, multistep API checks and heartbeat monitors are available, and traces connect a failed check to backend spans through OpenTelemetry. A free Hobby plan includes a monthly quota of API and browser check runs; Starter and Team plans add runs, locations and collaboration, and Enterprise adds SSO and private locations inside your own network.

Checkly fits teams that already write Playwright tests and want one source of truth for end-to-end testing and production monitoring. It requires coding and is not a full observability suite, so it is a poor fit for non-technical teams who only want uptime pings. Better Stack and UptimeRobot are simpler for basic uptime and status pages, Datadog Synthetics suits teams already on Datadog, and Grafana Cloud offers synthetic monitoring inside its own stack.

Datadog is a New York-based observability and security company, founded in 2010 and listed on Nasdaq. Its SaaS platform unifies infrastructure metrics, application performance monitoring and distributed tracing, log management, real user monitoring, session replay, synthetic tests, security monitoring and incident management, with more than 900 integrations that collect data from clouds, containers, databases and services.

Data flows through a single agent into shared dashboards and monitors, so a slow request can be followed from a frontend session through traces and logs down to the host or container. Watchdog applies anomaly detection automatically, and Bits AI helps investigate incidents with natural-language questions. Products are sold separately and priced per host, per volume or per event: infrastructure monitoring per host, APM per host, logs per GB ingested plus indexing, and so on. A free tier covers up to five hosts with short retention, but real deployments require several paid products.

Datadog fits scale-ups and enterprises running complex cloud and Kubernetes infrastructure that want one tool rather than a stitched stack. The main drawback is cost: bills grow with hosts, custom metrics and log volume, and teams need active governance to avoid surprises. Grafana Cloud and the open-source Prometheus, Loki and Tempo stack are cheaper for teams willing to assemble more themselves, New Relic offers usage-based pricing with a large free allowance, and Better Stack or Sentry cover smaller teams' needs at a fraction of the price.