Kafka Consumer Group Visualizer

See how a Kafka consumer group splits topic partitions across members — and what happens when you scale consumers up or down.

Kafka Consumer Group Visualizer

Assign topic partitions across consumers in a group. Add or remove consumers to trigger a rebalance and watch lag concentrate or spread.

    Simplified cooperative sticky-style assignment: partitions are spread round-robin across consumers. In Kafka, idle consumers beyond partition count get no partitions — and only one consumer in a group reads a given partition at a time.
    Things to try
    1. Set partitions = 6, consumers = 3 → even split.
    2. Add consumers past 6 → extras stay idle.
    3. Click Simulate lag tick → owned partitions drain, idle/unowned lag grows.
    4. Remove a consumer → rebalance piles more partitions onto survivors.