# isPublicKeyCompressed

Checks if a public key is in compressed format (starts with `02` or `03`, 33 bytes).

***

### Usage

```ts
import { isPublicKeyCompressed } from '@stacks/transactions';

isPublicKeyCompressed(
  '0367b23680c33a3adc784b80952f9bba83169d84c6567f49c9a92f7cc9c9b6f61b'
); // true

isPublicKeyCompressed(
  '04171ee91c13f2007bd22c3280987d113e9ffdb2f10631783473899868e67dcdb876f2be26558ea1d4194a96a3707aff085c96a643d43e02c0e9e67c5d47a7dac6'
); // false
```

[**Reference Link**](https://github.com/stx-labs/stacks.js/tree/main/packages/transactions/src/keys.ts#L131)

***

### Signature

```ts
function isPublicKeyCompressed(publicKey: PublicKey): boolean;
```

***

### Returns

`boolean`

`true` if the public key is compressed, `false` otherwise.

***

### Parameters

#### publicKey (required)

* **Type**: `PublicKey` (`string | Uint8Array`)

The public key to check.