# Uploading data to Storage

*Canonical: https://makerkit.dev/docs/next-supabase-lite/data-fetching/uploading-data-to-storage*

---

To upload data to Supabase Storage, we can use the Supabase JavaScript client. 

## Uploading a file

To upload a file, we can use the `upload` method.

For example, the code below is the code that uploads a user's profile image to the `avatars` bucket:

```ts
async function uploadUserProfilePhoto(
  client: SupabaseClient,
  photoFile: File,
  userId: string
) {
  const bytes = await photoFile.arrayBuffer();
  const bucket = client.storage.from('avatars');
  const extension = photoFile.name.split('.').pop();
  const fileName = `${userId}.${extension}`;

  const result = await bucket.upload(fileName, bytes, {
    upsert: true,
  });

  if (!result.error) {
    return bucket.getPublicUrl(fileName).data.publicUrl;
  }

  throw result.error;
}
```

You can also combine the above with `useSWRMutation` from `SWR` when you use the code above from a React component:

```ts
import useSWRMutation from 'swr/mutation';

function useUpdateProfile() {
  const client = useSupabase();
  const key = 'useUpdateProfile';

  return useSWRMutation(key, async (_, { arg: data }: { arg: {
    file: File;
    userId: string;
  } }) => {
    return updateUserData(client, data);
  });
}
```

And then, you can use it like this:

```tsx
const updateProfile = useUpdateProfile();

<Form onUpload={(file: File, userId: string) => {
  return updateProfile.trigger({ file, userId })
} />
```