Prometheus vs Grafana: Metrics Collection vs Visualization
Overview Prometheus is a time-series database that scrapes and stores metrics with its own query language and alerting engine, while Grafana is a visualization layer that queries Prometheus (and many other backends) to render dashboards. They’re often deployed together, not as alternatives, because each solves a different half of the observability pipeline. Comparison Diagram PrometheusGrafanaExporters / TargetsScrape EngineTSDB (storage)PromQLAlertmanagerOther DataSources(MySQL, Loki...)DashboardsAlerting + NotificationsPromQL queryCollects & Stores MetricsQueries & Visualizes Comparison Table Aspect Prometheus Grafana Primary purpose Collect, store, and query time-series metrics Visualize and correlate data from one or more sources Data collection Pull-based scraping of HTTP /metrics endpoints on a schedule None — has no collector, relies entirely on configured data sources Data storage Built-in on-disk time-series database (TSDB) Stateless; stores only dashboard/config metadata, not metric data Query language PromQL, native to its own TSDB Delegates to whatever query language the connected data source uses Supported data sources Only its own TSDB (federation aside) 150+ backends including Prometheus, Loki, InfluxDB, Elasticsearch, SQL Alerting Native alerting rules evaluated in-server, routed via Alertmanager Unified alerting engine that layers on top of any connected data source Visualization Minimal built-in expression browser, no dashboarding Rich, customizable panels, graphs, and shareable dashboards Typical deployment Runs per cluster/environment alongside exporters Central server pointing at multiple backends across teams Key Differences Prometheus owns the TSDB; Grafana holds no metric data of its own. Prometheus scrapes targets directly; Grafana only issues read queries. Prometheus alerting runs server-side via Alertmanager; Grafana’s alerting spans any connected source. Grafana supports multi-source dashboards, unlike Prometheus’s single-source expression browser. Neither replaces the other — most stacks run both together. When to Use Each Prometheus ...