Nelio A/B Testing uses cookies to run experiments and to track visitor information. The cookies identify a visitor and her session, specify whether that visitor participates in the running experiments and, if she does, in which ones, and keep track of the alternative a visitor has viewed so that she always sees the same alternative, offering a consistent and coherent user experience.


Nelio uses the following cookies to track visitors and campaign information:


  • nelioab_is_in and nelioab_was_in: This cookie is generated whenever a visitor accesses your website, and specifies whether she participates in the running experiments or not. Booth cookies are session cookies, which means they'll be erased when the browser is closed.
  • nelioab_userid: This cookie contains a unique visitor identifier. Our plugin uses this information for determining which visitors fulfill your goals. This cookie does never expire.
  • nelioab_session: Similar to the previous cookie, it uniquely identifies a visitor's session. It is a session cookie.
  • nelioab_env: This cookie specifies the group of experiments a visitor participates in.
  • nelioab_altexp_{ID}: These cookies are generated for each A/B experiment in your site (there is one cookie per experiment). It specifies the specific alternative the user is supposed to see.
  • nelioab_xglobal_altexp_{ID}: Similar to the previous cookies, these are generated for your global experiments. The x portion of the cookie specifies the kind of global experiment it refers to: c is for CSS experiments, m is for Menu experiments, t is for Theme experiments, and w is for Widget experiments.

Note: All cookies (if not stated otherwise) expire in three months (90 days).