[docs](https://k6.io/docs/using-k6/checks/)
In [[k6 (tool)|k6]], checks are conditions that responses are tested against. The outcome of the check can be used to either fail or pass a request. The number of passes or failures of the requests can be summed up at the end of the test.
## Text verification
Checks are commonly used for verifying that a string has been found in the response body:
```js
import { check } from 'k6';
import http from 'k6/http';
export default function () {
let res = http.get('http://homepage.com/');
check(res, {
'Homepage text verification': (r) => r.body.includes('Login'),
});
}
```
When used in conjunction with [[Parallel requests in k6|Batching in k6]], however, it will look something like this:
```js
export function Home () {
group('Home', function () {
let res = http.batch([
['GET', domain],
['GET', 'https://nicolevanderhoeven.github.io/css/style-dark.css'],
['GET', domain + '/lib/font-awesome/css/all.min.css'],
]);
check(res, {
'Homepage text verification': (r) => JSON.stringify(r).includes('Maastricht')
});
});
}
```
Checks can be combined with [[Thresholds in k6]] to pass or fail a test based on the outcome of these checks.