By default, Firefox does not support Integrated Windows Authentication and you are prompted for a User Name and Password when accessing such a site. The following steps outline how to override this default behavior, and trust specific site(s) for silent NTLM authentication.

---
title: Configure Firefox for Integrated Windows Authentication
author: Jon LaBelle
date: April 28, 2020
source: https://jonlabelle.com/snippets/view/markdown/configure-firefox-for-integrated-windows-authentication
---

# Configure Firefox for Integrated Windows Authentication

By default, [Firefox](https://www.mozilla.org/firefox/new/) does not support
[Integrated Windows Authentication](https://docs.microsoft.com/aspnet/web-api/overview/security/integrated-windows-authentication)
and you are prompted for a **User Name** and **Password** when accessing such a
site. The following steps outline how to override this default behavior, and
trust specific site(s) for silent NTLM authentication.

1. Open **Firefox**.
2. Type `about:config` in the URL address bar.
3. In the **Search preference name** field, type `ntlm`.
4. Double-click the `network.automatic-ntlm-auth.trusted-uris` field to edit the value.
    - **Enter a comma-separated list** comprised of URLs, domain names, host or computer names, then click OK. For example, type:
    ```
    http://server1.mydomain.com,https://server1.mydomain.com,MyComputerName,http://ServerName`
    ```

    > **NOTE** For security reasons, make this list as restrictive as possible.
5. **Restart Firefox** for the changes to be applied.

## References

- [Microsoft: Understanding HTTP Authentication](https://docs.microsoft.com/en-us/dotnet/framework/wcf/feature-details/understanding-http-authentication)
- [Microsoft: Integrated Windows Authentication](https://docs.microsoft.com/en-us/aspnet/web-api/overview/security/integrated-windows-authentication)
- [XIA Configuration Server: Configure Firefox for Integrated Authentication](https://www.centrel-solutions.com/media/xiaconfiguration/adminguideweb/FirefoxIntegratedAuthentication.html)
- [Centrify Server Suite: Configuring Firefox to allow silent authentication](https://docs.centrify.com/en/css/2018-html/#page/Java_web_servers/Configuring_Firefox_to_allow_silent_authenticati.3.html)