How to test a Grafana data source

Testing a Grafana data source confirms that Grafana can reach the backend behind a saved connection before dashboards, Explore queries, or alert rules depend on it. Use the data source settings page after creating a connection, changing credentials, moving an endpoint, or investigating a dashboard that stopped returning data.

The Settings tab runs the plugin's health check through Grafana. For a Prometheus data source, Save & test queries the Prometheus API and returns a success message when the URL, authentication settings, and network path from the Grafana server are usable.

The user testing the connection needs permission to edit or administer the data source. A successful data source test proves the connection health check, not every dashboard query; use Explore or the query inspector when the next question is whether a specific query, time range, or panel transformation works.

1. Open Connections → Data sources in Grafana.

   The data source list shows the saved name, plugin type, connection URL, and default marker when one data source is selected as the organization default.

2. Select the data source that needs a connection test.

   Use an address that the Grafana server can reach. In separate containers, localhost points inside the Grafana container, so a Docker service name or host-reachable address is usually required.

3. Check the Settings tab values and scroll to the bottom of the page.

   Leave the saved values unchanged when only retesting an existing connection.

4. Click Save & test and confirm that Grafana shows a green success message for the data source.

   Save & test saves any changed settings before running the plugin health check. A Prometheus data source reports Successfully queried the Prometheus API. Other plugins can return plugin-specific success text, but failed tests should be fixed before relying on dashboards, Explore, or alert rules that use the source.