The `next` badge in the header indicates that you're using Gitlab's canary version. Currently, its visibility is toggled on the client-side: https://gitlab.com/gitlab-org/gitlab-ce/blob/master/app/assets/javascripts/main.js#L147 The cookie itself is defined when toggling canary on or off at https://next.gitlab.com/ The fact that the badge's visibility is toggled on the client-side causes some flashes in the frontend:  A way of fixing this would be to: 1. Set the cookie on the server-side 2. Do the cookie check on the server-side and set a class (eg. `.canary-enabled`) where appropriate (`body`/`header`/...) when rendering pages 3. Toggle the badge's visibility with CSS 4. Cleanup Js responsible for toggling the visibility as it won't be needed anymore