AlertSleep is a 24/7 uptime monitoring service that instantly alerts you when your website, API, or server goes down — before your customers notice. Get notified within 60 seconds of downtime via SMS, phone call, email, Slack, or webhook. AlertSleep monitors HTTP/HTTPS endpoints, REST APIs, TCP ports, SSL certificates, and page speed from multiple global locations (North America, Europe, and Asia), using multi-location verification to eliminate false positives. Unlike other monitoring tools, AlertSleep includes phone call alerts and SMS on every paid plan — no premium upgrades or usage credits required. The Pro plan also offers unlimited team members with no per-seat pricing, making it ideal for growing teams and agencies managing multiple client sites. Key features include: 1-minute monitoring intervals on all paid plans SSL certificate expiration alerts (30, 14, and 7 days in advance) Public status pages that update automatically during incidents 365-day data retention on the Pro plan REST API for programmatic access Free diagnostic tools (SSL checker, DNS lookup, port checker, and more) Plans start at $0/month with a generous free tier, scaling to just $10/month for the full-featured Pro plan. Perfect for startups, SaaS companies, e-commerce stores, developers, and agencies who need enterprise-grade reliability without the enterprise price tag.