Remove HTML extension with web config permanently

URLRewrite 2.0 rule (insert this part inside system.webServer node) that replaces .html from url:

<rewrite>
    <rules>
        <rule name="Hide .html ext">
            <match ignoreCase="true" url="^(.*)"/>
            <conditions>
                <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true"/>
                <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true"/>
                <add input="{REQUEST_FILENAME}.html" matchType="IsFile"/>
            </conditions>
            <action type="Rewrite" url="{R:0}.html"/>
        </rule>
        <rule name="Redirecting .html ext" stopProcessing="true">
            <match url="^(.*).html"/>
            <conditions logicalGrouping="MatchAny">
                <add input="{URL}" pattern="(.*).html"/>
            </conditions>
            <action type="Redirect" url="{R:1}"/>
        </rule>
    </rules>
</rewrite>

If you want to do this on a per-website basis using the local IIS server on Windows 10, install the URL Rewrite module and then put this in web.config in the root of your virtual directory:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <rewrite>
            <rules>
                <remove name="Redirecting .html ext" />
                <remove name="Hide .html ext" />
                <rule name="Hide .html ext" enabled="true">
                    <match url="^(.*)" ignoreCase="true" />
                    <conditions>
                        <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
                        <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
                        <add input="{REQUEST_FILENAME}.html" matchType="IsFile" />
                    </conditions>
                    <serverVariables />
                    <action type="Rewrite" url="{R:0}.html" />
                </rule>
                <rule name="Redirecting .html ext" enabled="true" stopProcessing="true">
                    <match url="^(.*).html" />
                    <conditions logicalGrouping="MatchAny">
                        <add input="{URL}" pattern="^(.*)\.html$" />
                    </conditions>
                    <serverVariables />
                    <action type="Redirect" url="{R:1}" />
                </rule>
            </rules>
        </rewrite>
    </system.webServer>
</configuration>