ExpandOps

Access Code Lite lets you require a simple URL parameter code (e.g. ‘?access_code=enter123’) before visitors can view your site. 
Simply share the private access link (e.g. https://example.com?access_code=enter123) that the plugin generates to any user who you wish to grant access. 
Ideal for development, staging, previews, or private sharing without complex authentication.
Features: 
– Set a custom access code from the plugin settings page. 
– Code can be 3–12 characters, letters and numbers only. 
– Session persistence (default): visitors only need to enter the code once per visit. 
– Logged-in users, WordPress login, password reset, admin, AJAX, and cron are always allowed.
Important: Access Code Lite is not a security plugin. 
It does not encrypt, hide, or protect sensitive data. It only adds a simple URL parameter check and should be used for low-risk scenarios like development, staging, or preview access. 
Do not rely on this plugin to secure private or confidential information.
More persistence options (cookies, tokens, etc.) will be added in future versions.

Access Code Lite

Restrict site access with a simple URL code parameter and grant access using private link sharing. Ideal for sites in development or maintenance.

Access Code Lite vs WPvivid — Backup, Migration & Staging