What is Alertmanager used for?

Alertmanager is the Prometheus component that receives alerts from clients, then deduplicates, groups, silences and routes them to receivers such as email, PagerDuty and Opsgenie. It is a good fit for on-call alert routing for Prometheus, reducing alert noise with grouping and silencing alerts during maintenance.

Is Alertmanager open source?

Yes. Alertmanager is open source under the Apache-2.0 licence. Its source code is on GitHub at prometheus/alertmanager and is written mainly in Go.

Is Alertmanager free?

Yes. Alertmanager is open source, so the software itself is free to use.

Can I self-host Alertmanager?

Yes. Alertmanager can be self-hosted on your own server or infrastructure.

What is Alertmanager an alternative to?

Alertmanager is an open-source alternative to xMatters. Other open-source alternatives to xMatters include Keep, Alerta and OneUptime.

Is Alertmanager actively maintained?

Yes. The most recent commit to Alertmanager was on 1 October 2026, and the latest release is v0.34.1, published on 17 September 2026. The project has 8.6k stars on GitHub.

Alertmanager: open-source alternative to xMatters

About Alertmanager

Alertmanager is the part of the Prometheus ecosystem that processes alerts sent by client applications, most often the Prometheus server. Instead of notifying people for every raw alert, it deduplicates and groups them, and routes them to the right receiver integrations.

Receivers include email, PagerDuty and Opsgenie, and the webhook receiver allows many other mechanisms. It also takes care of silencing alerts for a period and inhibition, where one alert suppresses others that it makes redundant. Routing is configured in YAML with a tree of routes starting from a root route that must have a receiver, plus global settings such as the SMTP host for mail notifications.

Alertmanager is written in Go and licensed under Apache-2.0. You can install it from precompiled binaries on prometheus.io, run the Docker image from Quay.io or Docker Hub, or build it from source with Go and Node.js, and the web interface is served on port 9093 by default. It suits any team that runs Prometheus and needs structured on-call notifications.

Key features

Alert deduplication and grouping
Routing tree to receivers
Email, PagerDuty and Opsgenie integrations
Webhook receiver for custom targets
Silences for muting alerts
Inhibition rules to suppress duplicates
Docker images and binaries

Good fit for

→On-call alert routing for Prometheus
→Reducing alert noise with grouping
→Silencing alerts during maintenance

Built with: Go
Tags: alertmanager; prometheus; alerting; monitoring; notifications; pagerduty; observability; golang

Alertmanager: questions and answers

What is Alertmanager used for?: Alertmanager is the Prometheus component that receives alerts from clients, then deduplicates, groups, silences and routes them to receivers such as email, PagerDuty and Opsgenie. It is a good fit for on-call alert routing for Prometheus, reducing alert noise with grouping and silencing alerts during maintenance.
Is Alertmanager open source?: Yes. Alertmanager is open source under the Apache-2.0 licence. Its source code is on GitHub at prometheus/alertmanager and is written mainly in Go.
Is Alertmanager free?: Yes. Alertmanager is open source, so the software itself is free to use.
Can I self-host Alertmanager?: Yes. Alertmanager can be self-hosted on your own server or infrastructure.
What is Alertmanager an alternative to?: Alertmanager is an open-source alternative to xMatters. Other open-source alternatives to xMatters include Keep, Alerta and OneUptime.
Is Alertmanager actively maintained?: Yes. The most recent commit to Alertmanager was on 1 October 2026, and the latest release is v0.34.1, published on 17 September 2026. The project has 8.6k stars on GitHub.