With Transformations, you can change data as it flows through Segment to either correct bad data or customize data for a specific destination. Change event and property names to align events with your Tracking Plan, or to conform to a destination-specific requirement. For example,a Transformation could be created to change an event name from`completed_order` to`Order Completed` to conform to[Segment's ecommerce spec](/docs/connections/spec/ecommerce/v2/#order-completed).

With Transformations, you can change data as it flows through Segment to either correct bad data or customize data for a specific destination. Change event and property names to align events with your Tracking Plan, or to conform to a destination-specific requirement. For example,you can create a Transformation to change an event name from`completed_order` to`Order Completed` to conform to[Segment's ecommerce spec](/docs/connections/spec/ecommerce/v2/#order-completed).

You can also use[Segment's Public API](https://docs.segmentapis.com/tag/Transformations){:target="_blank"} to transform events, properties, and property values for many[use cases](#use-cases).

-**Transformations cannot be applied retroactively:** They only apply to data moving forward. However, you can manually extract and re-send (or even[Replay](/docs/guides/what-is-replay)) events through a source with an active destination Transformation, which will send the transformed events to your destinations.

-**Transformations areonlyavailable to Protocols customers:** If you're interested in this feature, contact your Account Executive or CSM to learn more about the Protocols package.

-**Transformations are available to Protocols customers:** If you're interested in this feature, contact your Account Executive or CSM to learn more about the Protocols package.

-**Source-level transformations are irrevocable:** When applied at the source, a transformation permanently changes the structure of the event. The original events are not easily recoverable or[Replayable](/docs/guides/what-is-replay). Assume that transformed data cannot be recovered.

-**Device-mode destinations are NOT supported:** Source scoped transformations will**only** apply to cloud-mode destinations, warehouses, and S3 destinations. Destination scoped transformations will**only** apply to cloud-mode destinations.

-**Add a new property name and assign a value:** If you want to create a new property and set a static value, use[Segment's Public API](https://docs.segmentapis.com/tag/Transformations){:target="_blank"} to create`new_property: static_value`. This transformation is in beta.

-**Change property value casing:** Transform property value casing to lowercase, uppercase, or title case. For example, Transform the property value`united states` to`USA` to remain consistent with your data tracking.