---
title: Forward auth
Using forward auth uses your existing reverse proxy to do the proxying, and only uses the authentik outpost to check authentication and authorization.
To use forward auth instead of proxying, you have to change a couple of settings.
In the Proxy Provider, make sure to use one of the Forward auth modes.
## Single application
Single application mode works for a single application hosted on its dedicated subdomain. This has the advantage that you can still do per-application access policies in authentik.
## Domain level
In the Proxy Provider, make sure to use the _Forward auth (domain level)_ mode.
This mode differs from the _Forward auth (single application)_ mode in the following points:
- You don't have to configure an application in authentik for each domain
- Users don't have to authorize multiple times
There are however also some downsides, mainly the fact that you **can't** restrict individual applications to different users.
The only configuration difference between single application and domain level is the host you specify.
For single application, you'd use the domain which the application is running on, and only `/outpost.goauthentik.io` is redirected to the outpost.
For domain level, you'd use the same domain as authentik.
