Webflow does not natively provide a way to password-protect specific CMS item pages, but there is a workaround to achieve this without the need for complex programming or 3rd party services.
Cloneable;
https://webflow.com/made-in-webflow/website/cms-page-login
For very simple, insecure solutions, you could build a large modal overlay that blocks your page from view. Entering the right password would then delete the overlay element using Javascript, and make your page visible.
This is very insecure, but may be useful for simple marketing solutions and portfolios.
A reverse proxy can provide a much more secure solution for your content, and can be adapted to different requirements ( user login, v. password-only ).
Sygnal builds reverse proxy solutions for our clients which can password-protect and content-gate any specific page on your site. Contact us for details.
In Webflow, password protection is a page-level settings. In CMS pages, this means the password applies to all of the item pages in the collection, with no direct ability to password-protect specific items only.
To achieve item-level passwords you'd need to build a custom solution based on your needs. There are two main factors;
The low security approaches are basically to toss a password into a field in the CMS, and then when it exists, you display a full-screen dialog over top of your page content until the password is entered. It's low security because your content is still there, and it can be thwarted with developer tools, and is dependent on JS being enabled in the browser.
Medium security approaches are to actually gate content access so that only those with the password can access it. This requires a reverse proxy, or else storing the content somewhere else and fetching it after server-side authorization.
The higher security approaches have the same design approach as the medium security systems, but adds individual user accounts and a registration process. This means a reverse proxy plus a membership framework like Netlify Identity or Webflow User accounts ( + some special engineering ).