Clickhouse ships with several built-in web tools that most people don’t know about. No installation, no setup - just hit the right endpoint on port 8123.

Accessing the dashboards

If your Clickhouse server isn’t directly accessible, create an SSH tunnel:

ssh -L 8123:127.0.0.1:8123 your-clickhouse-server

Now localhost:8123 points to your server.

The dashboards

/dashboard - Operations overview

http://localhost:8123/dashboard

Real-time insight into server internals. Shows queries, memory usage, merges, replication lag - basically a live view of system.* tables in a nice UI. This is your first stop when something feels slow.

/merges - Merge history

http://localhost:8123/merges

Visualizes the history of merge processes. Useful when you’re debugging high part counts or wondering why your table isn’t consolidating. Shows merge duration, parts involved, and throughput.

/play - SQL playground

http://localhost:8123/play

Run queries directly in the browser without needing a SQL client. Syntax highlighting, query history, result formatting. Handy for quick checks when you don’t want to fire up DataGrip or the CLI.

Other endpoints

  • /binary - Visualizes the Clickhouse binary structure. More of a curiosity than a tool.
  • /replicas_status - Simple HTTP health check. Returns OK if replicas are healthy. Good for load balancer health checks.

Why this matters

When you’re SSHed into a server at 2 AM debugging a production issue, having a built-in dashboard beats writing ad-hoc queries against system tables. Bookmark these.