If you're evaluating Vigilmon vs k6 (Grafana k6), you're probably asking the wrong question — not because one is better, but because these tools solve fundamentally different problems. k6 is a load and performance testing tool; Vigilmon is a continuous uptime monitor. Understanding when each applies will save you from building the wrong safety net for your production services.
What Is k6?
k6 (now Grafana k6) is an open-source developer-centric load and performance testing tool. It lets you write JavaScript-based test scripts that simulate concurrent user traffic against your API or application, measuring how the system performs under stress.
k6's key use cases:
- Load testing: simulate N virtual users hitting your endpoints simultaneously
- Stress testing: push beyond expected traffic to find breaking points
- Spike testing: model sudden traffic bursts to check autoscaling behavior
- CI/CD integration: run performance thresholds as automated gates before deployments
- Performance regression detection: compare response times across releases
k6 scripts run on demand — you invoke them before a launch, after a deployment, or in a CI pipeline. When the test run ends, so does k6's visibility into your service.
k6 Cloud (the hosted commercial extension) adds distributed test execution from multiple cloud regions, richer analytics, and team collaboration. But even in cloud mode, k6 is fundamentally a point-in-time tool — it checks how your service performs under artificial load at a specific moment.
What Is Vigilmon?
Vigilmon is a continuous uptime monitor with multi-region consensus alerting. It checks your live endpoints from multiple geographically distributed probe nodes on a recurring schedule and alerts you the moment a real outage is detected — around the clock, every day, without you running anything.
Vigilmon's core properties:
- Always-on: checks run every 1–5 minutes continuously, not on demand
- Multi-region consensus: an alert fires only when N independent probe nodes agree the service is down — eliminating false positives from transient single-node network events
- Low latency detection: real outages surface within minutes, not hours
- Zero-ops: no scripts to write, no test infrastructure to maintain
Vigilmon monitors HTTP/HTTPS endpoints, TCP ports, and cron job heartbeats. It includes response time history with color-coded latency bands, embeddable status badges, and webhook notifications for Slack, PagerDuty, or any custom endpoint.
Core Difference: Pre-Launch vs Post-Launch
The clearest way to frame k6 vs Vigilmon:
| Dimension | k6 | Vigilmon | |---|---|---| | When it runs | On demand (pre-launch, CI, ad hoc) | Continuously (24/7/365) | | What it measures | Performance under artificial load | Availability of live production service | | Who triggers it | Engineer or CI pipeline | Nobody — it's automatic | | Primary output | Load test report with latency percentiles | Alert when service is down or degraded | | False positive protection | N/A | Multi-region consensus | | Scripting required | Yes (JavaScript) | No | | Free tier | Yes (open-source) | Yes (5 monitors, no credit card) | | Cloud pricing | k6 Cloud from ~$89/month | Vigilmon paid from a fraction of that |
k6 answers: "Can my service handle 500 concurrent users before I launch?" Vigilmon answers: "Is my service up right now, and has it been up all day?"
k6 Cloud vs Vigilmon: Pricing
k6 Open Source
The open-source k6 CLI is free to run locally or on your own infrastructure. You get full scripting capability, metrics output, and CI integration at zero license cost. The ceiling is your own hardware and network bandwidth for generating load.
k6 Cloud (Grafana Cloud k6)
k6 Cloud provides managed test execution across Grafana's cloud regions. Pricing is based on virtual user hours (VUH):
- Free: 50 VUH/month
- Paid: starts around $89/month for 500 VUH, scaling with usage and team seats
For teams running frequent load tests — daily CI gates, pre-launch stress tests, ongoing performance benchmarks — k6 Cloud is well-priced for what it delivers. But it's a different budget line than uptime monitoring.
Vigilmon
Vigilmon's free tier is a permanent, standalone offering:
- Up to 5 monitors (HTTP, TCP, heartbeat)
- 5-minute check intervals
- Multi-region consensus on every check
- Email + webhook alerts
- Response time history
Paid plans scale monitor counts, check frequency (down to 1-minute intervals), and team seats. The cost is a small fraction of k6 Cloud because the infrastructure cost model is fundamentally different — monitoring probes versus load generation infrastructure.
Complementary Tools, Not Competitors
The practical recommendation: use both.
Use k6 before you launch to validate that your service can handle expected traffic patterns. Set performance thresholds — p95 response time under 300ms at 200 concurrent users — and fail the CI build if they're breached. Catch scaling problems before your users encounter them.
Use Vigilmon after you launch to know the moment something breaks in production. Your k6 tests told you the service could handle load; Vigilmon tells you the service is actually up and responding correctly right now.
A typical developer workflow:
- Write a k6 script for the critical user path (login → dashboard → API call)
- Set performance thresholds and add k6 to CI
- Deploy after k6 passes
- Add the production URL to Vigilmon with a 1-minute check interval
- Configure alerts to your Slack channel
- Know within minutes if a deployment broke something in production
Neither tool replaces the other. k6 is your pre-launch quality gate; Vigilmon is your post-launch safety net.
When to Use k6
- Load testing a new service before launch
- CI/CD performance gates on every deployment
- Stress testing to find breaking points and capacity limits
- Comparing performance across API versions or infrastructure changes
- Spike testing to validate autoscaling behavior
When to Use Vigilmon
- Continuous availability monitoring for production services
- Alerting when a live service goes down or becomes unreachable
- TCP port monitoring for non-HTTP services (databases, message queues)
- Cron job heartbeat monitoring to detect silent job failures
- Response time trending to catch gradual degradation before it becomes an outage
The Bottom Line
k6 and Vigilmon serve different phases of the service lifecycle. k6 is your pre-launch confidence check — it proves your service can handle load before you expose it to real users. Vigilmon is your post-launch sentinel — it watches continuously and alerts you the moment your live service fails.
If you're only running k6 and not running continuous uptime monitoring, you have a blind spot: you know your service could handle load last Tuesday when you ran the test, but you have no automatic signal when it goes down tonight.
If you're only running Vigilmon without load testing, you know your service is up — but you might not know it'll fall over when traffic spikes.
Run both. The combined cost of Vigilmon's free tier and k6's open source CLI is zero.
Start monitoring your live services for free at vigilmon.online — no credit card required.
Tags: #monitoring #loadtesting #devops #k6 #performance