> ## Documentation Index
> Fetch the complete documentation index at: https://checklyhq.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# What is Checkly?

> The Application Reliability Platform built for modern engineering teams.

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Checkly is an Application Reliability platform that enables teams to **test, monitor, and observe** their web applications, APIs, and other services using a developer or agentic workflow. Built for modern teams, Checkly uses combines a UI, [APIs](/api-reference/overview), and a [CLI](/cli/overview) to help define your monitoring setup autonomously and integrate directly into CI/CD pipelines.

### Improving reliability and stability with Checkly:

Checkly has three core capabilities:

* **Detect**: Testing, Uptime Monitoring, and Synthetic Monitoring with Playwright.
* **Communicate**: Customizable Alerting, Dashboards, & Status Pages for clear communication.
* **Resolve**: Distributed full-stack tracing and AI-powered incident analysis and context.

## Why Checkly?

Checkly helps developers increase uptime and reliability, improve shipping velocity, and improve incident response time through a unified workflow that's scalable, automated, and AI-ready.

<Columns cols={1}>
  <Card title="Monitoring as Code" href="/concepts/monitoring-as-code" cta="Learn more" horizontal>
    Define your entire monitoring setup with TypeScript constructs instead of manual UI configuration.
  </Card>

  <Card title="Native Playwright Support" href="/detect/synthetic-monitoring/browser-checks/overview" cta="Learn more" horizontal>
    Browser monitoring powered natively by Playwright for fast, reliable end-to-end scenario monitoring.
  </Card>

  <Card title="Developer-First Experience" href="/cli/authentication" cta="Learn more" horizontal>
    Code-driven platform with constructs, APIs, and a CLI that manages the entire lifecycle of your monitors.
  </Card>

  <Card title="Unified Testing, Monitoring, Tracing, and Incident Management" href="/detect/testing/overview" cta="Learn more" horizontal>
    Unify testing, monitoring, and observability into a single workflow using Playwright and OpenTelemetry.
  </Card>

  <Card title="Reliable Error Detection" href="/concepts/results" cta="Learn more" horizontal>
    Detect both functional and performance errors in pre-production and production environments.
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</Columns>

## Use Cases

* **[Pre-Production Testing](/guides/sdlc-monitoring)** — Validate functionality and performance in staging before deployment, catching regressions early.
* **[Production Monitoring](/learn/monitoring/api-monitoring)** — Continuously monitor critical user journeys, API endpoints, and application performance.
* **[Transaction Monitoring](/guides/monitoring-ecommerce-apps-using-playwright)** — Monitor checkout flows, payment processing, and product catalog to prevent revenue loss.
* **[API Reliability](/learn/monitoring/api-monitoring)** — Ensure third-party integrations and internal APIs maintain expected response times and availability.
* **[Multi-Environment Validation](/concepts/environments)** — Test across different environments, browsers, and devices for consistent functionality.
* **[Compliance and SLA Monitoring](/learn/incidents/slo-sla-sli)** — Track uptime and performance metrics to meet SLAs and regulatory requirements.

## Checkly Is Best Fit For

**DevOps and SRE Teams** looking for programmable monitoring that integrates seamlessly with their existing infrastructure-as-code and GitOps workflows.

**Full-Stack Engineering Teams** who want to shift monitoring left and treat monitoring as an integral part of their development process rather than an afterthought.

**Engineering Teams Using Modern Web Technologies** who want monitoring that understands modern JavaScript frameworks, SPAs, and API-first architectures.