---
title: "Kafka Simulator"
description: "How to use the Kafka Simulator in your browser: tutorials, how-to guides, the scenario catalog, the terminal reference and the URL format."
url: https://monedula.dev/flock/docs/kafka-simulator/
---
The simulator models Apache Kafka 4.3 ([Fidelity](/flock/docs/kafka-simulator/concepts/fidelity/)). It is free and runs entirely in your browser, with no backend, no account and no telemetry of your scenarios. Its engine is seeded, so a scenario or a shared sandbox replays the same way every time ([How the simulator works](/flock/docs/kafka-simulator/concepts/how-the-simulator-works/)).

## Open it

[Open the playground](/kafka-simulator/playground/). With no link parameters it opens in free play: a blank sandbox with a three-broker cluster you can start changing right away. The [product page](/kafka-simulator/) says more about what the simulator is for.

## Where to start

- New to the simulator: [Run your first scenario](/flock/docs/kafka-simulator/tutorials/run-your-first-scenario/) steps through one scripted scenario with the Steps, Why, Inspector and Metrics tabs.
- Ready to experiment: [Build a cluster in free play and break it](/flock/docs/kafka-simulator/tutorials/build-a-cluster-and-break-it/) starts a sandbox, kills brokers until writes fail, and shares the result as a link.
- Looking for a scenario: the [scenario catalog](/flock/docs/kafka-simulator/reference/scenarios/) lists every scenario in this release by module, each with a link that opens it in the playground.
- Reading rather than clicking: the [scenario pages](/kafka-simulator/scenarios/) walk through every scenario in this release step by step, and the [troubleshooting pages](/kafka-simulator/troubleshooting/) start from a Kafka error or symptom and link to the scenario steps that reproduce it.
- Wondering what a release includes: [Features by release](/flock/docs/kafka-simulator/reference/features/) says which version introduced each free-play topology and tool, and the [roadmap](/flock/docs/kafka-simulator/reference/roadmap/) lists the versions and their themes. The [changelog](/kafka-simulator/changelog/) counts the scenarios each version adds.

## Reporting a problem

**report issue**, in the **⋯** menu of the playground's top bar, opens the public issue tracker; [Report an issue](/flock/docs/kafka-simulator/how-to/report-an-issue/) says what to include.

Apache Kafka, Kafka and the Kafka logo are trademarks of the Apache Software Foundation. The Kafka Simulator is an independent educational tool; it is not affiliated with, endorsed by or sponsored by the ASF.