Grafana OnCall and Vigilmon often appear in the same search results. Both show up when engineering teams search for "alert monitoring" or "uptime alert tool." But they solve fundamentally different problems — and understanding that difference will save you from paying for a complex alerting platform when you actually need a monitoring tool, or vice versa.
What Grafana OnCall Is
Grafana OnCall is an on-call management and alert routing platform originally developed as Amixr, acquired by Grafana Labs in 2021, and subsequently open-sourced as part of the Grafana ecosystem.
Its core job is not monitoring. It's routing. When an alert fires from Prometheus, Alertmanager, Datadog, or another observability source, Grafana OnCall decides:
- Who is currently on call?
- How do I reach them (phone, Slack, email, PagerDuty)?
- What happens if they don't acknowledge within 5 minutes?
- Which escalation chain applies to this alert type?
Its actual features include:
- On-call schedule management (rotations, shifts, overrides, time zones)
- Escalation chains (primary → secondary → manager if unacknowledged)
- Alert grouping and noise reduction
- Direct paging via Slack, phone, SMS, or push
- Integration as an Alertmanager webhook receiver
- Web and mobile interfaces for on-call engineers
Critically: Grafana OnCall does not check whether your site is up. It has no probe infrastructure. It receives alerts that other systems generate. To use Grafana OnCall, you first need a Grafana + Prometheus (or similar) stack running synthetic checks or metric-based availability rules. Without that stack, there is nothing for OnCall to route.
What Vigilmon Is
Vigilmon is a purpose-built external uptime monitoring platform. It actively checks your HTTP endpoints, TCP ports, and SSL certificates from multiple geographic regions — independently of your infrastructure — and alerts you when something goes wrong.
The defining feature is multi-region consensus: Vigilmon requires a quorum of geographically distributed probes to agree on a failure before firing any alert. A transient DNS blip in one AWS region, a momentary CDN hiccup, a flaky probe in one geography — none of these become 3 AM alerts. Only genuine, multi-region outages trigger the alarm.
Vigilmon also includes a built-in customer-facing status page, Slack and webhook alerts, and a response time history chart — everything a developer team needs to monitor availability and communicate incidents to users.
Feature Comparison
| Feature | Vigilmon | Grafana OnCall | |---|---|---| | HTTP/HTTPS endpoint monitoring | Yes — built in | No (requires Grafana + Prometheus) | | TCP port monitoring | Yes | No | | SSL certificate monitoring | Yes | No | | Multi-region consensus | Yes (default) | No | | On-call scheduling | No | Yes | | Escalation chains | No | Yes | | Alert routing (paging) | No | Yes | | Alert deduplication | No | Yes | | Built-in status page | Yes | No | | Slack / webhook alerts | Yes | Yes (as output) | | Requires existing observability stack | No | Yes | | Self-hostable | Yes (open source) | Yes (open source) | | Hosted free tier | Yes — 5 monitors | Yes — limited (cloud Grafana) | | Paid pricing | ~$10–20/month flat | Part of Grafana Cloud pricing | | Setup time | 2–5 minutes | Hours (stack setup required) |
The Fundamental Distinction: Detection vs. Routing
This distinction matters more than any feature list.
Grafana OnCall is not a monitoring tool. It's an on-call management tool.
It sits between your monitoring/alerting system and your engineering team. Its value is entirely in what happens after an alert has already been generated: routing it to the right engineer, at the right time, through the right channel, with the right escalation timeline. None of that works without an upstream system actually detecting the problem.
Vigilmon is the detection layer. It generates the alert in the first place — running checks from outside your infrastructure, from multiple global locations, and applying consensus logic to ensure the alert is real before it fires.
This means the two tools occupy different positions in the stack:
[Vigilmon] → detects outage → fires alert → [Grafana OnCall] → routes to engineer
If you're using Prometheus and Grafana already, Grafana OnCall is a natural fit for managing who gets paged. But Prometheus and Grafana metric-based checks are not the same as external uptime monitoring — they measure what your stack sees from inside, not what your users experience from outside.
The Observability Stack Requirement
This is the most important practical difference for teams evaluating Grafana OnCall:
To use Grafana OnCall, you need:
- A running Grafana instance (hosted or self-managed)
- A metrics source (Prometheus, Mimir, or a Grafana-integrated data source)
- Alertmanager configured with alerting rules
- Grafana OnCall configured as the Alertmanager webhook receiver
- On-call schedules, escalation chains, and integrations configured
For teams already deep in the Prometheus/Grafana ecosystem, this is a reasonable additional layer. For a team that doesn't have that stack — or wants external uptime monitoring that works independently of their internal observability setup — Grafana OnCall isn't useful in isolation.
Vigilmon requires:
- Sign up
- Add a URL
- Done
No pre-existing stack. No agents to install. No internal metrics. The monitoring runs from Vigilmon's external probes, which means it works even when your own infrastructure is completely down.
Who Should Use Each
Choose Grafana OnCall if:
- You're already running Grafana and Prometheus and want to improve how alerts route to your team
- You have on-call rotations with multiple people and escalation tiers
- You want fine-grained control over who gets paged and when
- Your team is comfortable managing the Grafana ecosystem
- The internal alerting complexity — which team, which severity, which escalation — is the actual problem you're solving
Choose Vigilmon if:
- You want to know when your website or API is down from the outside world
- You don't have (or don't want) a Prometheus + Grafana stack just for uptime monitoring
- False-positive alert fatigue is a concern (multi-region consensus addresses this directly)
- You need a customer-facing status page alongside monitoring
- You want monitoring that works in 5 minutes, not after a stack setup
- Budget and simplicity are priorities
Can You Use Both?
Yes — and the tools are genuinely complementary when used correctly:
- Vigilmon monitors your external endpoints from outside your infrastructure. When an outage is confirmed by multi-region consensus, it fires a webhook.
- Grafana OnCall receives that webhook and routes the alert through your on-call rotation and escalation chain.
If your team has grown to the point where on-call management is a real operational problem — multiple rotations, escalation tiers, complex routing logic — this combination covers both the detection and the routing layer cleanly.
For most developer teams and small engineering organizations, the on-call routing complexity that Grafana OnCall solves doesn't exist yet. Vigilmon's built-in Slack and webhook alerting routes to the right person without needing a separate on-call management platform.
Pricing Reality
Grafana OnCall is available in two modes:
- Open source (self-hosted): Free, but requires you to run Grafana, Grafana OnCall, and your observability stack yourself
- Grafana Cloud: Included in Grafana Cloud plans; the free tier allows limited use; IRM (Incident Response and Management, which includes OnCall) starts at $24/user/month on paid plans
The cloud pricing means that for a 5-person engineering team using Grafana Cloud IRM, you're looking at $120/month — before you've paid for the monitoring tool that feeds it.
Vigilmon:
- Free tier: 5 monitors, 1-minute check intervals, status page, Slack alerts, no credit card required
- Paid: ~$10–20/month flat, more monitors, 30-second intervals
- Self-hosted: ~$5/month VPS, unlimited monitors
For a team whose primary need is "know when our site is down and alert us," Vigilmon's free tier costs $0/month and is ready in minutes.
Conclusion
Grafana OnCall is excellent software for teams with real on-call management complexity. If you're coordinating rotations across multiple engineers, managing escalation chains, and routing alerts from a mature Grafana + Prometheus stack to the right team at the right time — it's the right tool for that problem.
But it isn't a monitoring tool. It doesn't check whether your endpoints are reachable. It doesn't know if your SSL certificate expired. It doesn't have external probe infrastructure.
Vigilmon is built for the problem that comes first: external uptime detection, from multiple geographic regions, with consensus-filtered alerting that only fires when something is genuinely broken for your users.
Start there. Add on-call management tooling when your team has the rotation complexity to justify it.
Start monitoring for free at vigilmon.online — 5 monitors, 1-minute intervals, status page, Slack alerts, no credit card required.
Tags: #monitoring #devops #grafana #oncall #uptime #sre #observability