Lockdown Mode limits web access to reduce prompt injection risk

Lockdown Mode is now available to all logged-in users across account types and workspaces as an optional opt-in advanced security setting. It limits access to the web and external services to reduce risk of data exfiltration from prompt injection attacks. When enabled, ChatGPT restricts network-enabled capabilities including live web browsing, deep research, agent mode, file downloads, and some web-derived image support. Personal users can enable via Settings > Security. Workspace admins can configure access through workspace settings and role-based access controls.