The Expression Browser

The Expression Browser is Prometheus' built-in web interface for running PromQL queries interactively. It allows you to explore metrics, test queries, and visualize results without needing any external tools.

Run PromQL queries directly in the browser. You can enter metric names or full PromQL expressions and execute them instantly to inspect current values or trends.

Switch between Table and Graph view.

• Table view shows instant values at the current point in time.
• Graph view displays how a metric changes over time, helping you spot trends and anomalies.

Try up. The up metric indicates whether targets are reachable:

• 1 → Target is UP (successfully scraped)
• 0 → Target is DOWN (scrape failed)

Try prometheus_build_info. This metric provides metadata about the running Prometheus instance, including version and build information.

The Expression Browser is ideal for quick checks, debugging scrape issues, and learning PromQL basics.