How to change and configure File Permissions (chmod 755 / 644)

For typical Linux hosting, 755 is a common directory permission and 644 is common for files, including PHP files served through the web server. These are starting points, not universal rules: ownership, the PHP handler, application requirements, and ACLs determine the right access.

PHP files do not normally need an executable bit. CGI or command-line executables may need different permissions. Sensitive configuration files may use 400 or 440 only when the required service user can still read them and the application does not need to write them. Windows hosting uses different permission controls.

1. In Plesk Files, find the specific file/folder and open its permissions control, where available.
2. Alternatively, use the permissions/properties control in an authorized file-transfer client such as FileZilla or WinSCP, if supported by the server/protocol.
3. Record the existing permissions, change only the required item, and verify the application afterward. Do not apply blanket recursive changes or 777 to solve an error; ask support when ownership or required access is unclear.