Siren vs Grafana OnCall
Grafana OnCall is free. Siren costs $10/month. So why would anyone pay for Siren?
Because "free" has a price.
The Short Version
Grafana OnCall is a solid open-source alerting tool. If you're already running Grafana and you have the DevOps capacity to self-host another service, wire up Twilio for phone calls, and maintain it all—it's a capable option.
Siren is for teams who just want the phone to ring when something breaks. No infrastructure to manage. No Twilio integration to build. No ongoing maintenance. $10/month.
What "Free" Actually Costs
Grafana OnCall is free to download. But to actually get a phone call when an incident happens, you need to:
- Host it yourself — Run the service, keep it updated, make sure it stays up (ironic for an alerting tool)
- Integrate Twilio — Set up an account, provision phone numbers, manage API credentials, handle billing
- Build the glue — Configure webhooks, test delivery, debug when calls don't go through
- Maintain it forever — Security patches, version upgrades, capacity planning
That's not free. That's trading dollars for hours.
If your on-call alerting system goes down at 2am, who's on-call for that?
Pricing
| Siren | Grafana OnCall | |
|---|---|---|
| Software cost | $10/month | Free |
| Hosting | Included | You run it |
| Phone calls | Included | Twilio (pay per call + your time) |
| SMS | Included | Twilio (pay per message) |
| Phone number | Included | Twilio (~$1-2/month + setup) |
| Maintenance | None | Ongoing |
| Total cost | $10/month | "Free" + Twilio + ops time |
For a small team, Twilio costs might run $5-20/month depending on volume. But the real cost is the time spent setting it up, debugging delivery issues, and keeping everything running.
Features
What Both Do
- On-call scheduling
- Escalation policies
- Alert routing
- Incident tracking
Where Grafana OnCall Has More
- Deep Grafana integration — If you're already running Grafana for dashboards and alerting, OnCall fits natively into that ecosystem
- More routing complexity — Advanced routing rules, multiple escalation chains, schedule layers
- Open source — You can see the code, modify it, self-host with full control
Where Siren Wins
- Zero infrastructure — Nothing to host, nothing to maintain
- Phone calls just work — Multiple telephony providers, automatic failover, no Twilio wrangling
- Unlimited seats — Add your whole team, same price
- Five-minute setup — Sign up, verify your phone, point your alerts at your Siren email
Infrastructure
You might wonder how a $10/month service stays reliable.
Siren runs on geo-redundant infrastructure across multiple regions. Our database is distributed across three locations. We use multiple telephony providers with automatic failover—if one has issues, your alerts still get through.
We don't publish an SLA yet—we're not at that stage. But we built Siren like we'd build it for ourselves: assume things will fail, and make sure pages still go out.
Meanwhile, your self-hosted Grafana OnCall instance is exactly as reliable as you make it.
Who Should Use Grafana OnCall
- Teams already deep in the Grafana ecosystem
- Organizations with dedicated DevOps capacity to run and maintain it
- Teams that need complex routing rules and advanced customization
- Anyone who genuinely enjoys running infrastructure
Who Should Use Siren
- Teams who want alerting to just work
- Small teams without dedicated DevOps to babysit another service
- Anyone who's done the Twilio integration math and decided it's not worth their time
- Organizations that would rather pay $10/month than think about telephony infrastructure
The Bottom Line
Grafana OnCall is a good tool. If you have the team to run it and the time to integrate Twilio, it can work well.
But if you just want the phone to ring when your monitoring detects a problem—without becoming a telephony integration expert—Siren does that for $10/month.
No Twilio. No self-hosting. No maintenance. Just alerts.
Siren is built by Split Rock AI. Questions? [email protected]