Checkly

Definition

Checkly is a synthetic monitoring and API testing platform that lets developers write monitoring checks as code, using Playwright-based browser scripts and API request assertions, to continuously verify that critical user flows and endpoints keep working in production. It is designed to integrate directly into developer workflows and CI/CD pipelines rather than being configured only through a separate dashboard-only tool.

Overview

Traditional uptime monitors verify that a URL returns a successful response, but that does not guarantee a multi-step user flow, like logging in, adding an item to a cart, and checking out, actually works end to end. Checkly was built to close that gap by letting engineers define monitoring checks as executable code — browser scripts using Playwright or API request sequences with assertions — so monitoring can verify real functional flows, not just basic reachability, and live in the same codebase and review process as the application itself. Mechanically, a Checkly check is a script, typically JavaScript or TypeScript, that Checkly runs on a schedule from its distributed infrastructure, executing either a headless browser session that clicks through a real user flow or a sequence of API calls with response assertions on status codes, body content, and timing. Failures trigger alerts through configured channels, and Checkly retains detailed run artifacts, including screenshots, videos, and trace files for browser checks, so a failure can be debugged without needing to reproduce it manually. Because checks are plain code, they can be version-controlled, reviewed in pull requests, and deployed through the same CI/CD pipeline as the application, using Checkly's CLI to define and manage checks as configuration. Checkly differs from simpler uptime tools like UptimeRobot and Pingdom by testing actual application behavior through scripted, multi-step interactions rather than just checking that a URL responds, putting it closer in spirit to end-to-end testing tools than to basic ping-based monitors. It also distinguishes itself from broader observability platforms like Datadog by focusing specifically on synthetic, outside-in verification of user-facing flows rather than combining that with infrastructure metrics, logs, or distributed tracing. In practice, engineering teams write Checkly checks alongside their application code to continuously verify that key flows — sign-up, checkout, search, critical API endpoints — keep working after every deployment, often running the same checks in CI before a release and then on a recurring schedule in production afterward. This "monitoring as code" approach appeals particularly to teams already comfortable with Playwright or similar testing tools, since check authoring reuses familiar testing patterns and assertions. The main trade-off is that writing and maintaining browser-script checks requires more engineering effort than configuring a simple uptime monitor, and Checkly is narrower in scope than full observability platforms, so teams still need separate tools for infrastructure metrics, logs, and distributed tracing. It is best suited to teams that specifically want confidence that critical user journeys work correctly in production, rather than teams whose only need is basic reachability monitoring.

Key Features

• Defines monitoring checks as code using Playwright-based browser scripts
• Supports API monitoring with scripted request sequences and assertions
• Runs checks on a schedule from distributed global locations
• Captures screenshots, videos, and traces for failed browser checks
• Integrates checks into CI/CD pipelines via a command-line interface
• Enables version control and code review of monitoring checks
• Provides alerting integrations with common incident tools
• Targets multi-step user flow verification, not just basic reachability

Use Cases

Alternatives

Frequently Asked Questions

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