> For the complete documentation index, see [llms.txt](https://docs.getblock.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.getblock.io/api-reference/robinhood/web3_sha3-robinhood.md).

# web3\_sha3 - Robinhood

Returns the Keccak-256 hash of the given data. Despite the method name `sha3`, this returns Keccak-256 (the pre-standardization variant), not the standardized SHA3-256 — same as Ethereum.

## Parameters

| Parameter | Type   | Required | Description                                        |
| --------- | ------ | -------- | -------------------------------------------------- |
| data      | string | Yes      | Hex-encoded data to hash (`0x...` prefix required) |

## Request Example

{% tabs %}
{% tab title="cURL" %}
{% code overflow="wrap" %}

```bash
curl --location --request POST 'https://shared.us-east-1.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "web3_sha3",
    "params": [
        "0x68656c6c6f20776f726c64"
    ],
    "id": "getblock.io"
}'
```

{% endcode %}
{% endtab %}

{% tab title="JavaScript (Axios)" %}

```javascript
import axios from 'axios';

const data = JSON.stringify({
    "jsonrpc": "2.0",
    "method": "web3_sha3",
    "params": [
        "0x68656c6c6f20776f726c64"
    ],
    "id": "getblock.io"
});

const config = {
    method: 'post',
    url: 'https://shared.us-east-1.getblock.io/<ACCESS-TOKEN>/',
    headers: {
        'Content-Type': 'application/json'
    },
    data: data
};

axios(config)
    .then(response => console.log(JSON.stringify(response.data, null, 2)))
    .catch(error => console.log(error));
```

{% endtab %}

{% tab title="Python (Requests)" %}

```python
import requests
import json

url = "https://shared.us-east-1.getblock.io/<ACCESS-TOKEN>/"

payload = json.dumps({
    "jsonrpc": "2.0",
    "method": "web3_sha3",
    "params": [
        "0x68656c6c6f20776f726c64"
    ],
    "id": "getblock.io"
})

headers = {
    'Content-Type': 'application/json'
}

response = requests.post(url, headers=headers, data=payload)
print(response.text)
```

{% endtab %}

{% tab title="Rust (Reqwest)" %}

```rust
use reqwest::Client;
use serde_json::json;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::new();

    let payload = json!({
        "jsonrpc": "2.0",
        "method": "web3_sha3",
        "params": [
                "0x68656c6c6f20776f726c64"
        ],
        "id": "getblock.io"
});

    let response = client
        .post("https://shared.us-east-1.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&payload)
        .send()
        .await?;

    let result: serde_json::Value = response.json().await?;
    println!("{:#?}", result);

    Ok(())
}
```

{% endtab %}
{% endtabs %}

## Response Example

{% code overflow="wrap" %}

```json
{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": "0x47173285a8d7341e5e972fc677286384f802f8ef42a5ec5f03bbfa254cb01fad"
}
```

{% endcode %}

## Response Parameters

| Field  | Type            | Description                       |
| ------ | --------------- | --------------------------------- |
| result | DATA (32 bytes) | Keccak-256 hash of the input data |

## Use Cases

* Computing function selectors for contract calls (first 4 bytes of `keccak256("functionName(types)")`)
* Computing storage slot positions for mappings and arrays
* Computing event topic hashes for Stock Token Transfer events

## Error Handling

| Status Code | Error Message     | Cause                                          |
| ----------- | ----------------- | ---------------------------------------------- |
| 403         | Forbidden         | Missing or invalid `<ACCESS-TOKEN>`            |
| -32602      | Invalid params    | Request parameters are missing or malformed    |
| -32603      | Internal error    | Server-side error while processing the request |
| 429         | Too Many Requests | Rate limit exceeded for your plan              |

## SDK Integration

{% tabs %}
{% tab title="ethers.js" %}
{% code overflow="wrap" %}

```javascript
import { ethers } from 'ethers';

const provider = new ethers.JsonRpcProvider('https://shared.us-east-1.getblock.io/<ACCESS-TOKEN>/');

// Generic JSON-RPC call (works for any method):
const result = await provider.send('web3_sha3', ["0x68656c6c6f20776f726c64"]);
console.log(result);

// Many standard methods have typed wrappers on ethers Provider,
// e.g. provider.getBalance(addr), provider.getBlock(n), provider.getTransaction(hash).
```

{% endcode %}
{% endtab %}

{% tab title="viem" %}

```javascript
import { createPublicClient, http } from 'viem';

const client = createPublicClient({
    transport: http('https://shared.us-east-1.getblock.io/<ACCESS-TOKEN>/')
});

// Generic JSON-RPC request (works for any method):
const result = await client.request({
    method: 'web3_sha3',
    params: ["0x68656c6c6f20776f726c64"]
});
console.log(result);

// Many standard methods have typed wrappers on PublicClient,
// e.g. client.getBalance({ address }), client.getBlock({ blockNumber }).
```

{% endtab %}
{% endtabs %}