Checkly

Checkly is a Berlin-based synthetic monitoring platform that has rapidly become the go-to tool for developer teams who want to monitor their APIs and web applications using real code rather than point-and-click configuration screens. Founded in 2018 by Hannes Lenke and Tim Nolet, Checkly raised a $20 million Series B led by Balderton Capital in 2024, with participation from Accel and CRV. The platform distinguishes itself from legacy monitoring tools by embracing a "monitoring as code" philosophy built natively on Playwright, the open-source browser automation framework from Microsoft.

Where traditional synthetic monitoring tools like Pingdom or Datadog Synthetics rely on proprietary scripting languages or visual recorders, Checkly lets you write monitoring checks as standard Playwright test files. This means the same end-to-end tests your QA team writes during development can be repurposed as production monitors, eliminating the disconnect between testing and monitoring that plagues most engineering organizations. It is a genuinely developer-first approach to observability.

Monitoring as Code with the Checkly CLI

The Checkly CLI is the backbone of the platform's developer experience. It provides a JavaScript and TypeScript-native workflow for coding, testing, and deploying synthetic monitors directly from your codebase. Monitoring configurations live alongside your application code in version control, enabling the same review, branching, and CI/CD workflows that developers already use for application deployments. You define checks as code using the Checkly SDK, test them locally, and deploy them with a single command.

This approach solves a persistent problem in DevOps: monitoring drift. When monitors are configured through web dashboards, they inevitably fall out of sync with application changes. By keeping monitoring definitions in the same repository as the application code, Checkly ensures that every pull request can include updated monitors. The CLI supports both JavaScript and TypeScript, and checks can import shared utility functions, making it straightforward to maintain DRY monitoring configurations across large projects.

Playwright-Native Browser Checks

Checkly's browser checks are powered by Playwright, giving you access to the full Playwright Test API for writing sophisticated end-to-end monitoring scenarios. Each check spins up a real Chromium browser instance, navigates your application, interacts with elements, fills out forms, and validates that critical user journeys complete successfully. This goes far beyond simple uptime pinging -- you are testing actual user workflows against your production environment.

Playwright Check Suites take this further by allowing you to run entire Playwright test suites as scheduled monitors. If your team already has Playwright tests for CI, you can promote them to production monitors with minimal modification. The tests run on Checkly's global infrastructure across 20+ data center locations, providing geographic coverage that would be expensive and complex to build in-house. Test results include screenshots, traces, and performance metrics for each step, making it straightforward to diagnose failures.

API Monitoring and Multi-Step Checks

For backend services, Checkly offers API checks that support GET, POST, PUT, DELETE, and other HTTP methods with full control over headers, authentication, and request bodies. You can write assertions against response status codes, headers, body content, and response times using a flexible assertion library. Multi-step API checks allow you to chain requests together, using values from one response in subsequent requests -- essential for testing authentication flows, CRUD operations, or multi-service API sequences.

API checks can be configured with setup and teardown scripts that run before and after each check execution. This is useful for creating test data, obtaining authentication tokens, or cleaning up resources after a check completes. The scripting environment provides access to common Node.js libraries, including Axios and the built-in crypto module, giving you significant flexibility in how checks are structured.

Alerting and Incident Response

When a check fails, Checkly supports alerts through Slack, PagerDuty, OpsGenie, email, SMS, and webhooks. The alerting system includes configurable thresholds and retry logic to reduce false positives -- you can require multiple consecutive failures before an alert fires, and specify degraded versus hard-failure thresholds for response time monitoring. Alert escalation policies ensure that the right team members are notified at the right time.

Checkly also provides public and private status pages that automatically reflect your monitoring results. These pages serve as a transparent communication channel during incidents, showing real-time service health without requiring manual updates. The status pages are customizable with your branding and can track individual services or grouped components, providing a professional interface for communicating system status to customers and stakeholders.

CI/CD Integration and Shift-Left Monitoring

One of Checkly's most powerful capabilities is its CI/CD integration. Using the Checkly CLI, you can run your monitoring checks as part of your deployment pipeline -- before changes reach production. This "shift-left" approach catches broken endpoints, degraded performance, and failed user journeys in staging or preview environments, preventing issues from reaching end users. Checkly integrates natively with GitHub Actions, GitLab CI, Jenkins, and other CI/CD platforms.

The test command in the CLI executes all defined checks against a target environment and returns results in standard test report formats. If any check fails, the pipeline fails, blocking the deployment. This creates a quality gate that ensures your monitors pass before new code ships, a practice that significantly reduces the frequency of production incidents caused by deployment regressions.

European Data Sovereignty and GDPR

As a Berlin-headquartered company registered in Germany, Checkly operates under EU jurisdiction and is fully GDPR compliant. The company's infrastructure and data processing practices adhere to European data protection regulations, making it a natural choice for EU-based engineering teams that need monitoring without cross-border data concerns. This is a meaningful advantage over US-based alternatives like Datadog, which is subject to the CLOUD Act and other US regulations that can compel data disclosure.

For organizations in regulated industries like finance or healthcare, Checkly's European base provides additional assurance. The platform does not require access to your application's internal data -- it monitors from the outside, simulating real user behavior. This means Checkly never processes your customers' personal data, reducing the GDPR compliance surface area compared to application performance monitoring tools that instrument your backend code.

Pricing and Plan Structure

Checkly offers a generous free Hobby tier that includes 10,000 API check runs and 1,500 browser check runs per month -- enough for small projects or proof-of-concept evaluations. The Team plan starts at $30 per month and scales based on check volume, offering significantly more runs along with features like team collaboration, private locations, and advanced alerting integrations. Enterprise plans add SSO, custom contracts, and dedicated support.

Compared to Datadog Synthetics, which charges per 10,000 test runs with separate pricing for API and browser checks (and often requires a broader Datadog subscription), Checkly's pricing is more transparent and typically more affordable for teams focused solely on synthetic monitoring. Pingdom's pricing, starting at around $15/month for basic uptime checks, is cheaper for simple use cases but lacks the code-first workflow and Playwright integration that define Checkly's value proposition.

Limitations and Considerations

Checkly is purpose-built for synthetic monitoring and does not offer real user monitoring (RUM), log management, or infrastructure monitoring. Teams needing a full-stack observability platform will need to pair Checkly with complementary tools like Grafana, Better Stack, or Elastic APM. The platform's code-first approach, while powerful for developer teams, may be less accessible to non-technical stakeholders who prefer visual monitoring configuration.

The Playwright dependency, while a strength for teams already using Playwright, means that organizations invested in Cypress or Selenium for their testing framework will need to learn a new tool or maintain separate monitoring scripts. Additionally, the Team plan pricing can escalate quickly for organizations running large numbers of browser checks at frequent intervals, as browser check runs consume more resources and are priced accordingly.

Who Should Choose Checkly

Checkly is ideal for development teams and SREs who want monitoring that integrates seamlessly with their existing code-first workflows. Organizations already using Playwright for testing will find the transition to Checkly nearly frictionless. European companies seeking GDPR-compliant synthetic monitoring from a Berlin-based vendor have a clear advantage here. Startups and scale-ups that value transparent pricing over the complexity of full-stack observability platforms will appreciate Checkly's focused approach. If you need a tool that bridges the gap between testing and monitoring while keeping your monitoring configurations in version control, Checkly is one of the strongest options available in 2026.