Domain Monitor vs Checkly

Checkly occupies a specific niche: developer-first synthetic monitoring. It's built around writing Playwright scripts and API checks in code, deploying them as monitors, and integrating monitoring into your CI/CD pipeline. Domain Monitor covers different ground — domain expiry, SSL certificates, DNS record changes, and uptime monitoring for domain owners and operators.

The two tools are largely complementary. Here's what each is best at.

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What Checkly Does

Checkly is built for developers who want to write their monitoring as code:

• Browser checks — Playwright-based end-to-end tests running on a schedule in the cloud
• API checks — HTTP request-based checks with assertions on response status, headers, and body
• Multistep checks — Sequences of API calls (like an OAuth flow or a checkout)
• Monitoring as code — Define checks in code using the Checkly CLI, check them into version control, deploy via CI/CD
• Alerting — Slack, PagerDuty, webhook, and other integrations

Checkly's core differentiator is the code-first approach. If you write Playwright tests for your application already, Checkly lets you turn those same scripts into production monitors. For teams that want to monitor critical user flows (login, checkout, key user journeys) with real browser automation, Checkly is one of the strongest tools available.

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What Domain Monitor Covers

Domain Monitor is focused on domain health monitoring:

• Uptime monitoring — HTTP/HTTPS response checks
• SSL certificate monitoring — Expiry alerts with configurable lead times
• Domain expiry monitoring — Advance warning before domains lapse
• DNS record monitoring — Alerts on any record change
• Nameserver monitoring — Immediate alert on nameserver changes
• WHOIS monitoring — Alerts on registration data changes
• Status pages — For communicating health externally

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Feature Comparison

Feature	Domain Monitor	Checkly
HTTP uptime monitoring	Yes	Yes (API checks)
SSL expiry alerts	Yes	Limited
Domain expiry monitoring	Yes	No
DNS record change alerts	Yes	No
Nameserver change alerts	Yes	No
WHOIS monitoring	Yes	No
Playwright browser tests	No	Yes
Monitoring as code / CLI	No	Yes
CI/CD integration	No	Yes
API assertions	Limited	Yes
Status pages	Yes	No

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The Different Monitoring Problems

Checkly answers: "Is my application doing what it should do, in the way users experience it?" — through real browser automation that clicks buttons, fills forms, and validates responses.

Domain Monitor answers: "Are my domain assets healthy?" — through monitoring that tracks expiry, DNS integrity, certificate validity, and registration changes.

Checkly won't catch:

• Your domain is 20 days from expiry
• Your nameservers changed overnight
• Your MX record was accidentally deleted
• Your SSL certificate expires next week

Domain Monitor won't catch:

• Your checkout flow breaks at step 3 due to a JavaScript error
• A third-party dependency is failing silently
• Your search returns wrong results
• Your login form fails for users with certain email formats

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Who Uses Both

The combination of Checkly and Domain Monitor covers two distinct monitoring layers:

• Checkly monitors application correctness — whether user-facing flows work as expected
• Domain Monitor monitors domain and infrastructure health — whether your domain assets are valid and unchanged

Development teams at SaaS companies that write Playwright tests often use Checkly for their application flows and Domain Monitor for domain health, with the two serving completely different purposes.

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Get Started

Domain Monitor monitors SSL, domain expiry, DNS records, and uptime from a free account. Create a free account.

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Related Reading

• How to Monitor Checkout Flows
• How to Monitor Login Pages and Authentication Flows
• API Returns 200 But App Is Broken
• Best Uptime Monitoring Tools for Small SaaS
• Domain Monitor vs Datadog