Displaying execution traces

Hardhat can display execution traces of your contracts when running tests, scripts, and tasks. This can be helpful for debugging and understanding the behavior of your contracts.

The --verbosity (or -v, -vv, -vvv, etc.) Global Option controls the amount of output shown during test execution, script runs, and deployments when using simulated networks.

Higher verbosity levels show more information in the execution traces, and display traces for more types of operations.

To try it out, run your tests with a higher verbosity level:

npm

npx hardhat test -vvv

pnpm

pnpm hardhat test -vvv

Yarn

yarn hardhat test -vvv

You can also use the long form:

npm

npx hardhat test --verbosity 3

pnpm

pnpm hardhat test --verbosity 3

Yarn

yarn hardhat test --verbosity 3

Tip

The default level is 2, so using -v actually reduces output (to level 1). Use -vvv or higher to see more output than the default.

Understanding the different verbosity levels

The verbosity levels behave slightly differently for Solidity tests and TypeScript tests, scripts, and tasks, but you can expect similar results for most cases. Read this section to understand the details of what each level shows in different contexts.

Solidity tests

Each level includes everything from the previous levels:

Level	What it adds
0	Test names and pass/fail status (failure details are always shown)
1	Decoded logs for failing tests
2	Decoded logs for passing tests (default)
3	Execution traces for failing tests; stack traces always collected
4	Execution traces for passing tests; setup traces for failing tests
5	Setup traces for passing tests

TypeScript tests, scripts, and tasks

In this case, the --verbosity flag controls which execution traces are shown for the different JSON-RPC calls made to your simulated network.

Note

The --verbosity flag only produces output when using simulated networks. It does not apply to external networks that you connect to through HTTP, like Mainnet, or tasks that don’t involve network connections (e.g., hardhat build, hardhat clean).

Level	What it shows
0 - 2	No execution traces (default)
3	Execution traces for failing transactions only
4	Execution traces for all transactions
5	All execution traces with no deduplication (shows gas estimations, repeated polling, etc.)