# Source: https://docs.coollabs.io/coolify/v3/settings.md

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.coollabs.io/llms.txt
> Use this file to discover all available pages before exploring further.

# null

Only users in the `root team` could configure system-wide settings.

## URL Instance Domain

> optional

You can specify a Fully Qualified Domain Name (FQDN, eg: [https://example.com](https://example.com)) for your Coolify instance.

Without this configuration you need to use `<ip address>:3000` to reach your Coolify instance and all webhooks will be going to the ip address.

<Warning>
  If you change the domain name and you already have an existing integration with any Git provider, the webhooks (for autobuild and PR deployments, etc...) will fail. You need to reconfigure the URL manually in the GitHub/GitLab App.
</Warning>

## Default Redirect URL

> optional

Redirect not configured services to this page. Like if you set a DNS entry for `example.com`, but you do not have anything running on this domain, Coolify Proxy will redirect any requests to this `Default Redirect URL`.

## Rollback Coolify to a specific version

You can rollback Coolify to any previous version if something is broken on the latest one.

Example: 3.11.13

## Number of Docker Images kept locally

> default: 3

You can specify how many Docker images are kept locally for your applications. It helps you to revert to a previous state blazingly fast.

## Preview Domain Separator

> default: .

The separator used in the PR/MR previews.

With the default you get: `PRMRNumber.yourdomain.com`

If you set it to: `-` the preview domain will be: `PRMRNumber-yourdomain.com`

## Generate SSL for www and non-www

> default: off

You can specify if you would like to reach your Coolify instance on www & non-www as well, or just the defined FQDN ([https://example.com](https://example.com) -> non-www).

## Public Port Range

> default: 9000-9100

Port rage for on-demand TCP proxies (public databases), services (if need additional proxies).

<Tip>
  Allow these ports in your [firewall settings](./firewall.md).
</Tip>

## DNS Check

> default: on

By default, all DNS settings would be resolvable by Let's Encrypt servers and Coolify. If you are using behind a reverse proxy or tunnel, you can disable this check to prevent unnecessary errors.

## Custom DNS Servers

> optional

> default: the OS configured DNS servers will be used

If you have an internal DNS server, you can specify them here with comma separated a list, for example: `1.1.1.1,8.8.8.8`.

## Registration allowed

> default: on, but after the first registration, off.

After the first registration, this option is enabled to prevent unwanted registrations.

## Auto Update Coolify

> default: off

If enabled, Coolify checks for update every \~10 minutes and apply them automatically if there is a new version available.

<Tip>
  All resources (applications, databases, services) are keep running and available. Coolify does not required to run them. Only Git webhooks will fail during the update.
</Tip>

## Do Not Track

Set Do Not Track after installation.

## SSH Keys

You can add SSH Keys (private keys) to your Coolify instance, which can be used to connect to a [Remote Docker Engine](./destinations.md#remote-docker-engine).

## SSL Certificates

You can add custom SSL certificates to Coolify Proxy, even self-signed.

## Docker Registries

You can add custom Docker registries and set authentication for it to be able to:

* pull/push private images
* prevent to be rate limited