Matching conversions from within applications on a client device to interactions with content items presented with resources may include receiving first data associated with an interaction with a content item displayed with a resource. The first data includes an application identifier for an application associated with the content item and an account identifier. The matching may also include receiving second data from the client device associated with a conversion using the application. The second data includes the application identifier and a device identifier for the client device. The matching may further include receiving third data from the client device that includes the account identifier and the device identifier. The conversion can be determined as associated with the interaction with the content item displayed with the resource based on matching the second data with the first data based on the third data.