Cronitor

StatusCake

StatusCake is a website and infrastructure monitoring platform offering uptime monitoring, page speed tracking, SSL certificate expiration alerts, domain expiry and DNS monitoring, and server health monitoring. Paid plans check sites as frequently as every 30 seconds from more than 30 global monitoring locations.

Honeybadger

Honeybadger is a monitoring tool designed for web applications. It helps developers identify and fix errors, track uptime, and monitor cron jobs. With Honeybadger, you can ensure your application is running smoothly and fix issues before they affect your users.

Healthchecks.io

Healthchecks.io is a cron job monitoring service that flips the usual uptime-check model: instead of pinging your server, your scheduled job pings a unique URL Healthchecks.io generates for it, and the service alerts you if that ping doesn't arrive within an expected period and grace time. It's been operating since 2015 and supports cron expressions for defining exactly when a job is expected to run. The service integrates with more than 30 platforms for notifications and incident management, including Slack, Discord, Telegram, Microsoft Teams, PagerDuty, Opsgenie, email, SMS, and generic webhooks, plus GitHub Issues and Prometheus. It offers a free tier for monitoring up to 20 cron jobs with no credit card required, along with paid tiers for more checks, and the project is also open source and self-hostable.

Checkly

Checkly is an active monitoring platform that lets engineering teams run synthetic API and full‑stack browser checks. It uses Playwright under the hood to simulate real user interactions and verify that endpoints and UI flows stay healthy. The service provides scheduled runs, alerting, and dashboards so teams can catch regressions before customers notice them. It integrates with common DevOps tools and supports CI/CD pipelines for continuous reliability.