# Device identifiers

There are two ways to identify a particular device registered with Pushwoosh – a hardware ID (HWID) and a push token.

## HWID

HWID (or Hardware ID) is a key identifier assigned to the device by Pushwoosh SDK.

#### Android HWID

For Android devices, HWID is a random set of letters and digits generated by the first app with the Pushwoosh SDK installed on the device. It's later shared with other apps that contain Pushwoosh SDK so that all such apps will have the same HWID as a result.

However, if a user deletes all the apps with Pushwoosh SDK and then re-installs some, a new HWID will be generated once again.

Android HWID example: `5dcaed99-e1e0-44dc-bde2-b96188b99e9e`

#### iOS HWID

For iOS devices, IDFV ([Identifier for Vendor](https://developer.apple.com/documentation/uikit/uidevice/1620059-identifierforvendor)) is being used as a HWID of the device. It won't change as long as there is at least one app from the same vendor installed on the device.

iOS HWID example (upper case only!): `CBAF8ED1-17FB-49A3-73BD-DC79B63AEF93`

## Push token

Push token (device token) is a unique key for the app-device combination issued by the Apple or Google push notification gateways. It allows gateways and push notification providers to route messages and ensure the notification is delivered to the unique app-device combination for which it is intended.

#### iOS push token

iOS device push tokens are strings with 64 hexadecimal symbols. iOS push token example: `03df25c845d460bcdad7802d2vf6fc1dfde97283bf75cc993eb6dca835ea2e2f`

<Aside type="caution">
Make sure that the iOS push tokens you use when targeting specific devices in your API requests are in **lower case**.
</Aside>

#### Android push token

Android device push tokens can differ in length (usually below 255 characters) and typically start with APA91b…. However, it might also have a colon-separated prefix. Android push token example: `APA91bFoi3lMMre9G3XzR1LrF4ZT82_15MEICogXSLB8-MrdkRuRQFwNI5u8Dh0cI90ABD3BOKnxkEla8cGdisbDHl5cVIkZah5QUhSAxzx4Roa7b4xy9tvx9iNSYw-eXBYYd8k1XKf8Q_Qq1X9-x-U-Y79vdPq`

<Aside type="caution">
Using raw device tokens for targeting specific devices is not the most reliable way because FCM push tokens tend to change from time to time, and it’s hard to tell how often it occurs.
</Aside>

<Aside type="caution" title="Important">
To obtain the HWID and push token, you'll need assistance from your development team. Please share [this link](/developer/pushwoosh-knowledge-hub/device-identifiers#how-to-obtain-hwid-and-push-token) with them for detailed instructions.
</Aside>