[](https://github.com/cucumber/tag-expressions/actions/workflows/test-go.yml) [](https://github.com/cucumber/tag-expressions/actions/workflows/test-java.yml) [](https://github.com/cucumber/tag-expressions/actions/workflows/test-javascript.yml) [](https://github.com/cucumber/tag-expressions/actions/workflows/test-perl.yml) [](https://github.com/cucumber/tag-expressions/actions/workflows/test-python.yml) [](https://github.com/cucumber/tag-expressions/actions/workflows/test-ruby.yml) # Tag Expressions Tag Expressions is a simple query language for tags. The simplest tag expression is simply a single tag, for example: @smoke A slightly more elaborate expression may combine tags, for example: @smoke and not @ui Tag Expressions are used for two purposes: 1. Run a subset of scenarios (using the `--tags expression` option of the [command line](https://cucumber.io/docs/cucumber/api/#running-cucumber)) 2. Specify that a hook should only run for a subset of scenarios (using [conditional hooks](https://cucumber.io/docs/cucumber/api/#hooks)) Tag Expressions are [boolean expressions](https://en.wikipedia.org/wiki/Boolean_expression) of tags with the logical operators `and`, `or` and `not`. For more complex Tag Expressions you can use parenthesis for clarity, or to change operator precedence: (@smoke or @ui) and (not @slow) ## Escaping If you need to use one of the reserved characters `(`, `)`, `\` or ` ` (whitespace) in a tag, you can escape it with a `\`. Examples: | Gherkin Tag | Escaped Tag Expression | | ------------- | ---------------------- | | @x(y) | @x\\(y\\) | | @x\y | @x\\\\y | ## Migrating from old style tags Older versions of Cucumber used a different syntax for tags. The list below provides some examples illustrating how to migrate to tag expressions. | Old style command line | Cucumber Expressions style command line | | ----------------------------- | --------------------------------------- | | --tags @dev | --tags @dev | | --tags ~@dev | --tags "not @dev" | | --tags @foo,@bar | --tags "@foo or @bar" | | --tags @foo --tags @bar | --tags "@foo and bar" | | --tags ~@foo --tags @bar,@zap | --tags "not @foo and (@bar or @zap)" |