Cookie Management

Dynamic Yield stores personal information in cookies and local storage to create targeted experiences on the web. Listed cookies and local storage entries are divided into logical groups.

Most cookies are used by Dynamic Yield JavaScript sources, which are implemented on your site. These are stored on your second-level domain (SLD). Cookies representing personal identifiers are also stored on the dynamicyield.com domain.

When working with the Experience OS display ad feature without setting up a custom domain, the content is served by a Dynamic Yield domain (adserve.io). This domain then also hosts cookies designated to your SLD.

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Cookie time to live:
In accordance with EU privacy guidelines, we limit storage of all cookies to a maximum of 365 days.

Personal identifiers

Personal identifiers used for tracking:

Name	Description	Cookie / TTL	Local Storage	Cookie Domain
DYID	Dynamic Yield unique anonymous identifier. This is a secure cookie.	✔ / 1 year		dynamicyield.com
_dyid	Dynamic Yield unique anonymous identifier.	✔ / 30 days	✔	Customer's SLD
_dyid_server	Dynamic Yield unique anonymous identifier. For more information, see Safari Intelligent Tracking Prevention Policy and DYID Retention	✔ / 1 year		Customer's SLD
_cfduid	Used to identify individual clients behind a shared IP address and apply security settings on a per-client basis.	✔ / 1 year		dynamicyield.com
DYSES	Dynamic Yield session identifier. This is a secure cookie.	✔ / browser session		dynamicyield.com
_dy_lu_ses	Session identifier for landing URL condition targeting.	✔ / browser session	✔	Customer's SLD

Experimentation

A group of values used for experimentation in various Dynamic Yield objects.
Values are not personally identifying:

Name	Description	Cookie / TTL	Local Storage	Cookie Domain
_dy_ses_load_seq	Internal state in experimentation to detect browser sessions.	✔ / 30 days	✔	Customer's SLD
_dy_soct	Indicates the last time an action occurred, used for frequency settings (once per day, for example).	✔ / 1 year	✔	Customer's SLD
_dy_csc	Keeps track of events for the “Elapsed time” condition.	30 days	✔
_dyexps, _dy_att_exps	Keeps state of experiment selections and attribution.	30 days	✔
_dy_c_exps, _dy_c_att_exps	Keeps state of persistent experiment selections (legacy, empty entry for most customers).	✔ / 30 days	✔	Customer's SLD

Mechanics

A group of values tracking specific browser behavior (clock drift, browser
closure, interrupted calls to the server, and so on). Values are not personally identifying:

Name	Description	Cookie / TTL	Local Storage	Cookie Domain
_dy_csc_ses	Empty session cookie to notice close of browser.	✔ / browser session		Customer's SLD
_dy_toffset	Validation for client’s clock drift (for computers that don’t sync their clock with the Internet – as was observed in Eastern Europe).	✔ / 30 days	✔	Customer's SLD
_dyrc	User engagement actions that are yet to be verified to be sent successfully to server from previous pageview. Should indicate whether another attempt to send should be done. Cleaned up on the next pageview.	30 days	✔	Customer's SLD
_dyfs	Indicates the first session.	✔ / browser session		Customer's SLD
dy_fs_page	Indicates the URL of the first page in the session	✔ / browser session
_dybatch	User engagement actions that are yet to be verified to be sent successfully to the server from the previous pageview. Should indicate whether another attempt to send should be done. Cleaned up on the next pageview.	30 days	✔
_dycmc	Assists in markup of cookie-deleter users.	✔ / 30 days	✔	Customer's SLD
_dyjsession	The session ID	✔ / browser session	✔	Customer's SLD
_dy_cs_storage_items	Management of custom cookies created by customer or Customer Success team.	✔ / 1 year		Customer's SLD

Segmentation

A group of values assisting in user segmentation (geography, device type, site variables
and so on). These are used for caching segmentation values for performance enhancement
and optimization. Values are not personally identifying:

Name	Description	Cookie / TTL	Local Storage	Domain
_dy_df_geo	Human-friendly country, state, city.	✔ / 30 days	✔	Customer's SLD
_dy_geo	Machine-friendly country, continent, area, city.	✔ / 30 days	30	Customer's SLD
_dyaud_sess	User state of the real-time audience segmentation system (session-oriented).	✔ / 30 days		Customer's SLD
_dyuss_<section_id>	Superficial usage data (session-oriented).	✔ / browser session	✔	Customer's SLD
_dy_weather_<section_id>	Cached weather forecast data (if applicable).	30 days	✔
_dy_tsrc	Cached “traffic source”.	30 days	✔
_dyaud_nchc	User state of the real-time audience segmentation system.	30 days	✔
_dyaud_page	Non-user state of the real-time audience segmentation system.	30 days	✔
_dycnst	GDPR consent user status	30 days	✔	Customer's SLD
_dy_device	Caches coarse device data (brand, and Tablet vs Smartphone).	30 days	✔
_dycst	Collects data about the user agent and window size.	✔ / 30 days	✔

Google Chrome 80 update (SameSite cookie)

Google Chrome 80 (February 4, 2020) introduced a new default cookie attribute setting and new requirements. To comply with their requirements, Dynamic Yield now marks all cross-origin cookies with the SameSite attribute value of none and marks them as Secure. This enables Dynamic Yield to function with no changes in behavior, and does not require any action on your part.

However, if Chrome does flag any cookies, they might be cookies that were created before this change was implemented. If you encounter any issues, check Dynamic Yield in incognito mode.