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title: Authenticate with Windows NTLM authentication in Postman
updated: 2024-08-16T00:00:00.000Z
search\_keyword: 'WWW-Authenticate, x-www-form-urlencoded'
max-toc-depth: 2
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Windows NTLM is the authorization flow for the Windows operating system and for standalone systems. NTLM is a challenge-response style authentication protocol.

To use NTLM authentication, do the following:

1. In the **Authorization** tab for a request, select **NTLM Authentication** from the **Auth Type** dropdown list.

2. Enter your **Username** and **Password** for NTLM access. You can optionally set advanced details, but Postman will try to generate values for them if necessary.

<Info class="iconless-callout">
  By default, your request will run a second time after extracting data received from the first request. You can turn off this behavior by selecting the **Yes, disable retrying the request** checkbox.
</Info>

Advanced parameters for NTLM auth are as follows:

* **Domain** - The domain or host to authenticate against.
* **Workstation** - The hostname of your PC.