# Using Placement Parameters

Define and consume placement parameters in paywalls across platforms, including web checkout query parameters.

Placement parameters let you pass context into a paywall and personalize content.

How to use:

1. In the paywall editor, create a variable.
2. Choose type: `parameter` and set the key name.
3. Reference the variable in your paywall text or logic.

Notes:

* Web Checkout: query string parameters (e.g. `?name=jordan`) are available as placement parameters. See [Web Checkout links](/docs/web-checkout/web-checkout-creating-campaigns-to-show-paywalls).
* Mobile SDKs: you can pass parameters when registering or retrieving paywalls. See platform guides for examples.

Platform guides:

* iOS: [`Presenting paywalls`](/docs/sdk/guides/advanced/presenting-paywalls)
* Android: [`Presenting paywalls`](/docs/sdk/guides/advanced/presenting-paywalls)
* Flutter: [`Presenting paywalls`](/docs/sdk/guides/advanced/presenting-paywalls)
* Expo: [`Presenting paywalls`](/docs/sdk/guides/advanced/presenting-paywalls)