4dayz is a web based application that provides a public messaging feed with a 96 hour lifespan. The platform is designed to operate without requiring users to provide an email address or phone number. Instead, access and participation are managed through a browser generated key ID. The service allows anyone to read the public feed instantly, and users can write to the feed by creating or using a browser key. Each public post remains visible in the feed for up to 96 hours, after which it is removed from the active stream. An archive containing the post content, the associated public key, and related IP security logs may be retained for up to three months. The primary workflow involves three steps. First, a user reads the public feed without creating an account. Second, they create a browser key ID without sharing personal contact information. Third, they submit a public message that stays in the feed for the 96 hour period. The application includes features for managing identity, such as restoring an ID using a 24 word recovery phrase, backing up the ID, and logging out. The recovery phrase is generated after the user confirms their current password, and it is used to restore the same signing and private message keys. The platform warns that anyone with access to this phrase can control the ID and advises keeping it offline and never sharing it. Technical details include the use of a password that encrypts the private key saved in the user's browser. The application cannot recover this password if it is lost. Users can create a new ID or use a key already saved in the browser. The interface also includes a live feed for updates and a privacy policy that outlines data retention practices. The application is accessible at the URL 4dayz.com and is described as a public feed that is not part of a user's permanent identity.