# How to conditionally load data with SWR

> Learn how to conditionally load data with SWR by passing null as the key until your data is ready, so the request only fires once you can make it.

Author: [Flavio Copes](https://flaviocopes.com/about/) | Published: 2021-07-25 | Topics: [JavaScript](https://flaviocopes.com/tags/js/) | Canonical: https://flaviocopes.com/swr-conditionally-load-data/

Using SWR you might have this problem: you want to do the request only if you have some data.

For example, one case I had was, I had to figure out if the user was logged in before sending a request to a `/api/user` endpoint to get the user's data.

In particular, I had a `session` object, and inside it, a `user` object. Both needed to be defined.

So here's what I did:

```js
import fetcher from 'lib/fetcher'

...

const { data: userData } = useSWR(session && session.user ? `/api/user` : null, fetcher)
```

The first parameter is the URL. If it's `null`, then SWR does not perform the request, and solves the original problem.