> Markdown version of [Query Parameters](https://vaadin.com/docs/next/flow/routing/additional-guides/query-parameters). Section index: [llms.txt](https://vaadin.com/docs/next/flow/llms.txt)

# Query Parameters

You can retrieve any query parameters contained in a URL; for example, `?name1=value1&name2=value2`. [Route parameters](https://vaadin.com/docs/next/flow/routing/route-parameters.md) is the easiest way to pass extra information to a given route, and it should work for most common use cases. It’s, therefore, recommended to use query templates only if your use case isn’t achievable using [route parameters](https://vaadin.com/docs/next/flow/routing/route-parameters.md).

Use the `getQueryParameters()` method of a `Location` instance to access query parameters. You can retrieve the `Location` class through the `BeforeEnterEvent` parameter of the `BeforeEnterObserver::beforeEnter()` method or the `BeforeEvent` parameter of the `HasUrlParameter::setParameter()` method.

> **Note:** A `Location` object represents a relative URL made up of path segments and query parameters, but without the host name; for example, `new Location("book/search?keyword=Vaadin")`.

**Example**: Retrieving query parameters from a `BeforeEvent`.

```java
@Override
public void setParameter(BeforeEvent event,
        @OptionalParameter String parameter) {

    Location location = event.getLocation();
    QueryParameters queryParameters = location.getQueryParameters();

    Map<String, List<String>> parametersMap = queryParameters
            .getParameters();
}
```

> **Note:** `getQueryParameters()` supports multiple values associated with the same key; for example, `https://example.com/?genre=fiction&restrictions=16+&genre=classic` results in the corresponding map `{"genre" : ["fiction", "classic"], "restrictions": ["16+"]}}`.

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