(References omitted—use official vendor pages for PortableApps, Mozilla, Chromium, Brave, and DuckDuckGo extension pages.)
While there isn't a pre-packaged "DuckDuckGo Portable" app, you can achieve the exact same result by using the method. Since the DuckDuckGo browser is built on the same engine as Chrome, this is the most reliable workaround for Windows 8.1 users. duckduckgo browser download for windows 81 portable
Since the standalone browser is incompatible, the best way to get the DuckDuckGo experience on Windows 8.1 is by integrating their tools into an existing supported browser like Mozilla Firefox or Google Chrome . duckduckgo browser download for windows 81 portable