Uptime Tracker
Uptime Tracker monitors websites, APIs, servers and scheduled jobs around the clock, rechecking failures before sending alerts to help distinguish outages from brief network errors. It supports HTTP(S) and keyword checks, SSL certificates, TCP ports, DNS records, ping, domain expiry, authenticated API tests with JSON assertions, multi-step API workflows, gRPC, SMTP, IMAP and heartbeat monitoring for cron jobs and backups. Alerts can be routed through rules to email, SMS, Slack, Microsoft Teams, Discord, Telegram, Google Chat, PagerDuty, Pushover, ntfy, Gotify, Mattermost, Rocket.Chat and webhooks, with on-call schedules and escalation. The service includes incident timelines, maintenance windows, reports and hosted status pages on custom domains. Individuals, developers, SaaS teams, agencies, freelancers, online stores and small businesses can use it to monitor services and communicate availability. A free plan includes two monitors; paid plans start at $9 per month.
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AlertKick
AlertKick combines server security and uptime monitoring in one product. A lightweight eBPF agent for Linux detects intrusions, file changes, rootkits, and SSH activity (login alerts, failed-attempt auto-blocking, maintenance lock), with detections mapped to MITRE ATT&CK and AI triage that attaches a written verdict to each alert. External monitors check HTTP, TCP, and DNS from outside the network, with response-time thresholds, SSL certificate expiry, and domain expiry from live registry RDAP data. Heartbeat monitors catch silent cron and backup failures, and public status pages keep users informed. Alerts flow through escalation policies and on-call rosters to email, Slack, Telegram, WhatsApp, SMS, and phone calls. Server changes are recorded and attributed for compliance evidence, with PCI DSS and SOX reports on Business plans. Setup is a one-line install per server. The free plan includes 10 uptime monitors and heartbeats - no card, commercial use allowed.
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PagerDuty
PagerDuty, Inc. (NYSE:PD) is a leader in digital operations management. In an always-on world, organizations of all sizes trust PagerDuty to help them deliver a perfect digital experience to their customers, every time.
Teams use PagerDuty to identify issues and opportunities in real time and bring together the right people to fix problems faster and prevent them in the future. PagerDuty's ecosystem of over 350+ integrations, including Slack, Zoom, ServiceNow, AWS, Microsoft Teams, Salesforce, and more, enable teams to centralize their technology stack, get a holistic view of their operations, and optimize processes within their toolsets.
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upsonar.io
Most uptime monitors only check if your server responds. upsonar goes further — it loads your page and discovers every external dependency: CDN-hosted files, third-party scripts, web fonts, and API endpoints. If any of them fail, you get alerted before your users notice.
Availability checks run from multiple global regions simultaneously, so regional CDN failures and localized outages don't go undetected. Beyond uptime, upsonar monitors SSL certificates approaching expiration, tracks domain expiry dates to prevent renewal failures, and detects DNS record changes that could indicate unauthorized modifications.
All five monitoring types work together in one dashboard. Notifications reach you through email, Telegram, or webhooks compatible with Slack, Discord, and PagerDuty. Get started free with 3 websites — all features included, no credit card needed.
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