Checkly Alternative: Simple Uptime Monitoring vs Monitoring as Code

Checkly is built for engineering teams that want to define monitoring in code: Playwright browser checks, API checks and uptime monitors that live in a repository and deploy through CI. SiteDownCheck is a small free service for knowing when a site is down. Those are different jobs, so this comparison is less about which is better and more about which job you have.

Checkly details come from its public pricing page at the time of writing (October 2026). Plans and quotas change; check their site. Our details are on the pricing page.

What each is built for

Checkly's pricing page lists a free Hobby plan for personal projects, with a set number of uptime monitors, monthly run allowances for browser and API checks, and a handful of public locations. It lists email, Slack and webhook alerts on that plan, and SMS and phone alerts on paid plans. It also describes a CLI, Terraform and Pulumi integrations for monitoring as code. According to the page, free-plan checks stop when the monthly allowance is used up, so read the quotas before you rely on it for production.

SiteDownCheck is a form-driven uptime monitor. You paste a URL, pick a check type (HTTP, keyword, JSON, heartbeat) and an alert channel. There is no code, no CLI-driven workflow and no scripted browser.

Side-by-side

Where Checkly is stronger

• Real browser flows. A Playwright check can log in, add to cart and verify the confirmation page. An HTTP check sees a 200 from the login page while the login button is broken. If a revenue-critical flow is the risk, this is the capability that matters. Synthetic vs real user monitoring explains the trade-offs.
• Monitoring that ships with the code. If your checks live in the repo, they get reviewed, versioned and deployed with the app. Teams that already test with Playwright can reuse those scripts.
• Faster feedback and more locations. Shorter intervals and several regions mean quicker detection and a better view of regional problems.
• Developer ergonomics. Everything is scriptable, which our UI-first product is not.

Where SiteDownCheck fits better

• You do not want to write code. For a blog, a small shop or a client site, filling in a form is the right amount of effort.
• Everything operational is bundled. SSL expiry, domain expiry, DNS and certificate change alerts and maintenance windows come with the free plan, so you are not assembling that from scripts.
• No quota that stops checks. Our free plan has a fixed three monitors rather than a monthly run budget.
• Diagnosis tools. When something fails, use the HTTP status checker, redirect checker or outage root cause finder without leaving the site.

A practical split

Many teams do both: a code-defined browser check for the two or three flows that make money, and a plain uptime monitor for everything else. If you already have Checkly or a similar tool, you can add a free monitor as an independent second opinion that does not share a failure domain with your CI pipeline.

If you monitor APIs, our JSON validator helps you work out the expected response before you write the assertion, and the guide on monitoring API endpoints covers status, latency and body checks.

Honest limitations of ours

No scripted browser checks, no monitoring as code, one default location, 5-minute intervals. Pro is planned with more capability, but there is no date or price, and we will not suggest one here. If you need Playwright-grade checks today, use a tool that has them.

Next steps

• Start a free monitor and add a keyword check to confirm real content loads.
• Add a heartbeat monitor for scheduled jobs.
• Read how to monitor API endpoints.
• Review synthetic vs real user monitoring.
• Cut noise with reducing false alerts.

FAQ

Is Checkly free?

Its pricing page lists a free Hobby plan with monthly run quotas for browser and API checks. Check the page for current numbers.

Can SiteDownCheck run Playwright scripts?

No. We do HTTP, keyword, JSON and heartbeat checks, not scripted browser sessions.

Can I manage monitors from code with SiteDownCheck?

There is a free API with a limit of 200 requests per day, but we do not offer a Terraform provider or CLI-based workflow.

Is a keyword check a substitute for a browser check?

Partly. A keyword check confirms that expected text is in the response, which catches many broken deploys, but it cannot click through a flow.

Opinions here are our own; verify vendor details yourself. See our editorial policy and disclaimer.