# Retracer (https://docs-dmpho5eos-ton-core-docs.vercel.app/llms/tvm/tools/retracer/content.md)



<Callout type="note">
  Some explorers link to Retracer from transaction pages. For new debugging workflows, use [TxTracer](/llms/tvm/tools/txtracer/content.md) when possible.
</Callout>

[Retracer](https://retracer.ton.org/) is a classic TVM transaction tracing tool for inspecting transaction execution step by step. Use it to:

* inspect complex transaction flows;
* debug smart contract execution;
* review gas usage and fees.

Source code: [`ton-blockchain/tvm-web-viewer` on GitHub](https://github.com/ton-blockchain/tvm-web-viewer/).

<Image src="/images/retracer.png" darkSrc="/images/retracer.png" alt="Retracer screenshot" />

The screenshot shows the main parts of the Retracer interface:

* Transaction details show the sender, destination contract, transferred amounts, timestamp, logical time (LT), fees, and balances;
* <kbd>C5</kbd> button displays the action list for the transaction;
* <kbd>Logs</kbd> button displays detailed execution logs;
* On the left, the instruction list shows the TVM instructions executed by the contract;
* On the right, the stack panel shows the stack state for the selected instruction.