> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tenderly.co/llms.txt
> Use this file to discover all available pages before exploring further.

# Debugging Transactions

> Replay and debug a transaction on a Virtual Environment, step through its execution, and inspect state changes and revert reasons.

[Tenderly Debugger](/debugger/overview) is supported on transactions executed on the Virtual Environment. You can use it to inspect and debug transactions executed on your Virtual Environment with the same functionalities as if you were debugging real transactions.

For Debugger to work, it needs to come from a contract that has been verified on the parent network, Tenderly, or on the Virtual Environment.

Access Debugger by clicking on any transaction in the **Virtual Environment Explorer** and then on **Debugger**.

[Watch on Loom →](https://www.loom.com/share/09413e8a867f4ddeaa41a5080d771895?sid=b8f60cda-fcb8-401b-ba9a-8bb69630fe9a)

How can Debugger help you find and fix transaction errors?

* Navigate through the function calls of any transaction.
* Analyze emitted events and state changes.
* Get accurate gas usage details with [Gas Profiler](/debugger/gas-profiler).

If debugging reveals a logical error in the smart contract you're inspecting, you can use [Simulator UI](/simulator-ui/overview) with **Edit Source Code** to run the failing transaction against bug-fixed code. This is a quick way to validate the bug fix before applying it to the code-base and re-deploying.