Redirects are configured on the target document.

To configure a redirect from old-page.html to new-page.html edit new-page.md:

---
title: New page
redirect_from:
    - old-page.html
---

Make sure old-page.md does not exist.

htmlRedirectProcessor

Generates html-files with a HTML meta refresh. supported by all hosting services but does not respond with proper a proper HTTP 301 response.

redirectFileProcessor

Generate a Netlify-style _redirect file. Not supported by all hosting sevices but will respond with proper HTTP status codes.