ConsistentHTTPS is a Firefox web-browser extension that prevents going accidentally from HTTPS URLs to HTTP URLs in the same domain.

The extension works by automatically replacing the http protocol with the https in links and forms that lead to pages of the same site (including its subdomains) once the page is loaded.

The extension is universal, does not use any predefined URL databases and solely relies on the fact of opening the current page via the HTTPS protocol that guarantees the site is working when using HTTPS.

The extension starts to work immediately after installation and does not need browser restart.


The following extension options are available in the browser’s window “Add-on Manager” → “Extensions”:

Process subdomain URLs (disabled by default)
Enables processing links and forms that lead to subdomains of current domain.
Observe dynamic page changes (enabled by default)
Allows to automatically process new links and forms added to current page dynamically after the page has been initially loaded.


  • The extension’s functionality does not apply to cases when going to an HTTP URL happens not via a link or a form, but as a result of a redirection from the URL that the link or the form points to.
  • The extension does not determine automatically whether a site opened via HTTP is available via HTTPS.