Kowl - Open Source Web UI for Kafka

Kowl is a Web UI, that allows you to explore and find messages in Kafka, provides an overview about topic configuration, consumer groups, brokers etc. It is designed to be hosted by a platform team, so that the initial setup including SASL, TLS etc. only has to be made once for everyone - however you can also run it locally using docker (compose). It’s open source and licensed under Apache 2.0.


Features include:

  • Message viewer: Explore your topics’ messages in our message viewer through ad-hoc queries and dynamic filters. Find any message you want using JavaScript functions to filter messages. Supported encodings are: JSON, Avro, Protobuf, XML, Text and Binary (hex view). The used enconding (except Protobuf) is recognized automatically.
  • Consumer groups: List all your active consumer groups along with their active group offsets. You can view a visualization of group lags either by topic (sum of all partition lags), single partitions or the sum of all partition lags (group lag)
  • Topic overview: Browse through the list of your Kafka topics, check their configuration, space usage, list all consumers who consume a single topic or watch partition details (such as low and high water marks, message count, …), embed topic documentation from a git repository and more.
  • Cluster overview: List available brokers, their space usage, rack id and other information to get a high level overview of your brokers in your cluster.

Disclaimer: I’m one of the Kowl authors.

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Nice! Do you have any plans of adding kSQL console support to it?

Actually no plans at the moment, but feature requests via the GitHub issues are always welcome. We try to prioritize by community feedback.

However for kSQL I’m not sure if we are even allowed to offer features around it (because of the Confluent license). Maybe someone from Confluent can shed some light on this?

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